ComfyUI Course: Ep19 - SDXL & Flux Inpainting Tips with ComfyUI
Transform photos and illustrations by adding, removing, or refining details with ComfyUI’s inpainting and outpainting tools. Learn step-by-step workflows, advanced masking, and prompt techniques to achieve seamless, creative edits with SDXL and Flux.
Related Certification: Certification in Applying SDXL & Flux Inpainting Techniques with ComfyUI

Also includes Access to All:
What You Will Learn
- Build complete inpainting and outpainting workflows in ComfyUI
- Install and use Inpaint Crop and Inpaint Stitch custom nodes
- Choose and configure SDXL inpainting checkpoints
- Create precise masks and control context area and mask blur
- Tune denoise, prompts, seeds and sampler settings for best results
- Integrate external tools (e.g., Photoshop) for final blending and troubleshooting
Study Guide
Introduction: Unlocking Creative Power with Inpainting & Outpainting in ComfyUI
Imagine taking your favorite photo or illustration and rewriting its story,adding, removing, or correcting details with precision and creative control. That’s the promise of inpainting and outpainting, two of the most transformative techniques available to digital artists, designers, and anyone curious about generative AI. This course is your comprehensive guide to mastering these techniques in ComfyUI, focusing on SDXL for best results, with an honest look at integrating Flux and external tools. You’ll learn not only the “how,” but the “why”,equipping yourself with workflows, parameter tuning strategies, and creative insights that open up a world of visual possibility.
In this learning journey, you’ll move from foundational concepts to advanced workflows, dive deep into the nuances of custom nodes and parameter tuning, and explore creative troubleshooting with real-world examples. Whether you’re correcting mistakes, adding new elements, or expanding scenes beyond their original borders, you’ll leave this course empowered to use ComfyUI as your creative playground.
Understanding Inpainting and Outpainting: The Foundation
Before diving into the tools and workflows, let’s clarify what inpainting and outpainting mean in the context of ComfyUI and generative AI.
Inpainting is the art of modifying or filling in specific areas of an image,imagine erasing an object and seamlessly rebuilding what’s behind it, or swapping a shirt’s color while preserving the folds and lighting. Outpainting is the act of expanding an image: imagine extending a landscape beyond its borders, or giving your portrait a wider context.
Why does this matter? Because these techniques break the boundaries of conventional editing. They give you granular control,whether you want to fix a blemish, add a wild new element, or tell a brand-new story with the same starting image.
Two real-world examples:
1. Inpainting: You have a photo where a person is holding a coffee cup, but you want to replace it with a bouquet of flowers. Inpainting lets you mask the cup and generate the flowers, matching the lighting and perspective.
2. Outpainting: You have a square portrait, but you need a wide banner for a website. Outpainting allows you to extend the scene to the left and right, generating fitting background content that blends with the original.
ComfyUI: Your Node-Based Playground
ComfyUI is a node-based interface for stable diffusion models, providing unmatched flexibility and control over your image generation and manipulation workflows. Every action, from loading an image to crafting the perfect inpaint, is a connection of nodes, each with a specific purpose.
Why use ComfyUI for inpainting and outpainting? It’s the modularity. You can experiment, iterate, and refine every aspect of your workflow, from the choice of model (SDXL, Flux, etc.) to the mask’s shape and blur, all the way to the integration of external editing tools.
Installing Custom Nodes: The Essential Tools for Inpainting
One of the first key lessons: ComfyUI’s standard installation isn’t enough for advanced inpainting workflows. You’ll need to add specific custom nodes:
1. Inpaint Crop Node
2. Inpaint Stitch Node
Why are these critical? The Inpaint Crop node isolates the region you want to modify, cropping both the image and its mask to minimize unnecessary processing. The Inpaint Stitch node takes the AI-generated inpainted area and blends it back into your original image, making the change seamless.
How to install:
- Search for “inpaint crop” in the ComfyUI custom node manager.
- Locate the node (check for the author details, as suggested in the source).
- Click install, and wait for the process to finish.
Practical tip: If you ever struggle with inpainting results, double-check that these nodes are installed and updated. They’re non-negotiable for a professional workflow.
Example:
- Let’s say you want to replace a bird in a photograph. The Inpaint Crop node will extract just the region around the bird, and the Inpaint Stitch node will ensure your new bird (generated via AI) fits back into the original image with perfect alignment.
- If you skip these nodes, you’ll either process unnecessary image regions (wasting resources) or struggle with mismatched seams.
Choosing and Installing the Right Models: SDXL and Inpainting Checkpoints
All the magic of inpainting depends on the model you use. SDXL (Stable Diffusion XL) is currently the gold standard for high-quality, detailed, and context-aware image generation in ComfyUI.
But here’s the trick: While you can use a standard SDXL checkpoint, you’ll get far better results with a dedicated inpainting model checkpoint. These checkpoints are trained specifically for modifying masked regions, leading to more accurate and visually coherent results.
How to set up:
- Download the dedicated SDXL inpainting model checkpoint (usually labeled clearly from your model source).
- Place the checkpoint file in the “checkpoints” folder inside your ComfyUI directory.
- Select this model in your ComfyUI workflow when building your inpainting pipeline.
Example:
- You want to fix a blemish on a portrait. Using the SDXL inpainting checkpoint, the AI understands how to blend skin tones and lighting naturally, leading to a flawless correction.
- If you use a non-inpainting checkpoint, you might notice mismatched texture, lighting, or artifacts at the edges of your mask.
ComfyUI Inpainting Workflow: Step-by-Step Breakdown
Let’s walk through the process of setting up a robust inpainting workflow in ComfyUI, using SDXL as our model. This is the backbone of your creative process.
-
Load Your Image
Use the “Load Image” node to bring in your photo or illustration. This is your starting canvas. -
Edit Mask with Mask Editor
Activate ComfyUI’s Mask Editor. Here, you’ll paint the area you want to modify. You can adjust brush size, opacity, and switch between draw and erase modes for precision. The more accurate your mask, the more controlled your result; but some creative randomness can be achieved with rougher masks. -
Inpaint Crop Node
Connect the loaded image and the painted mask to the Inpaint Crop node. This node crops both the image and the mask to the smallest bounding box containing the masked area. This focuses your computation and improves result quality. -
Model Conditioning and Prompts
Feed the cropped image and mask into the inpainting model conditioning node. This is where you input your positive and negative prompts. Positive prompts describe what you want (e.g., “a bouquet of red roses”), negative prompts steer the AI away from unwanted features. -
K Sampler and Denoising
The K Sampler node is where the actual inpainting happens. Here you’ll set the denoise value,a critical parameter we’ll cover in depth shortly. You’ll also choose your seed, sampler algorithm, and steps. -
VAE Decode
After sampling, the image remains in “latent” (compressed) form. Use the VAE decode node to convert it back to a viewable image. -
Inpaint Stitch Node
Finally, the Inpaint Stitch node takes the inpainted crop and seamlessly blends it back into the original image. The result: a modified image with your new element or correction.
Throughout, you can preview, adjust, and iterate at each stage. Want a different result? Change the prompt, tweak the mask, or try a new seed.
Example 1:
You want to swap a character’s hat for a crown. Load the image, select the hat area with the mask editor, crop with Inpaint Crop, prompt “golden crown with jewels,” sample, and stitch. Experiment with different prompts for different crown styles.
Example 2:
Fixing a photo where a person has closed eyes: Mask the eyes, prompt “open eyes, natural gaze,” and let the workflow regenerate only the masked area, blending the new eyes into the original face.
Understanding the Mask Editor: Precision and Creativity
The mask is your steering wheel. It tells the AI exactly where to act,and where to leave things untouched. ComfyUI’s Mask Editor provides a set of intuitive tools:
- Brush Size and Shape: Adjust for broad strokes or tiny details. A large brush is useful for big areas (like outpainting), while a fine brush is vital for small corrections (like fixing a blemish).
- Opacity: Set how strong the mask effect should be. Lower opacity can create softer transitions.
- Draw/Erase Toggle: Switch between painting the mask or erasing parts of it for precision.
- Invert Mask: Sometimes you want to keep the masked area unchanged and modify everything else. For example, inverting the mask keeps a person’s head as-is while generating a new body and environment around it.
- Mask Blur: Blur the edges of your mask for smoother transitions. This is crucial for blending,if you see hard lines between the inpainted area and the original, increasing mask blur can help.
Example 1:
You want to change the color of a dress. Use the mask editor to carefully trace the dress, keeping the brush size small for edges. If a subtle line remains after inpainting, increase the mask blur for a seamless blend.
Example 2:
You want to generate a new background while keeping the original subject. Use the invert mask option,mask the subject, invert, and prompt for a new environment.
Best Practice: Take your time with the mask. A precise mask gives you granular control, but sometimes rough, broad masks deliver more creative or unexpected results. The only way to know is to experiment.
Context Area and Expand Factor: Giving the AI More to Work With
Sometimes the AI needs more context to generate realistic results, especially for edge modifications or outpainting. The “expand factor” in the Inpaint Crop node (or similar settings in outpainting nodes) increases the context area around your selection, letting the model “see” more of the surrounding image.
Why does this matter? If you’re inpainting an object at the edge of the image, a small context area might confuse the AI, leading to mismatched textures or lighting. Expanding the context gives the model more visual clues, resulting in smoother, more cohesive outputs.
Example 1:
You’re fixing the edge of a painting’s frame. Use a higher expand factor so the model considers not just the frame but also the wall and background, ensuring the new frame matches the scene.
Example 2:
You’re adding a reflection to a window. Expanding the context area allows the AI to analyze the existing reflections and lighting, creating a believable effect.
Tip: Context area isn’t always “more is better”,too much expansion can confuse the model or reduce the focus on the target area. Experiment to find the sweet spot for your specific image and modification.
Parameter Tuning: The Art and Science of Denoise
One of the most important,and often misunderstood,parameters is “denoise.” This setting determines how much freedom the AI has to reinterpret the masked region.
- Low Denoise: The AI tries to keep the modified area as close to the original as possible. Best for subtle corrections or when you want to retain existing details.
- High Denoise: The AI gets creative, potentially generating something entirely new. Perfect for dramatic changes, but can diverge significantly from the original image.
How to use it:
- Start with a moderate value (e.g., 0.5 to 0.7).
- If you’re not seeing enough change, increase denoise in small increments (0.1 at a time).
- If the result is too wild or inconsistent, lower the denoise.
Example 1:
You want to change a shirt’s color but keep the folds and shadows. Use a low denoise (0.3-0.5).
Example 2:
You want to add a new object (like a bird) to a scene. Use a higher denoise (0.7-1.0) to let the AI generate new content.
Best Practice: “Inpainting isn’t always perfect and you need to experiment with prompts and denoise values until you find a balance.” Make a habit of running several iterations with different denoise values and seeds,you’ll often be surprised by the variety and quality of results.
Prompt Engineering: Speaking the AI’s Language
Prompts are the bridge between your vision and the AI’s output. The quality of your prompt,what you say, how you say it, and what you exclude,dramatically impacts the inpainting result.
Tips:
- Be specific: “A small white cup” yields a different result than “a cup.”
- Use negative prompts: If you don’t want glasses on the character, include “no glasses” in your negative prompt.
- Iterate: Test variations and see which prompt yields the most satisfying result.
Example 1:
You want to inpaint a reflection in a window. Prompt: “Reflection of woman’s hair in the window, natural lighting.” Negative prompt: “no distortion, no extra objects.”
Example 2:
Adding an animal into a forest scene. Prompt: “A red fox sitting in the grass, natural posture.” Negative prompt: “no other animals, no blur.”
Best Practice: Combine prompt engineering with denoise tuning for best results. Sometimes a minor tweak to the prompt fixes issues that denoise changes alone can’t solve.
Outpainting in ComfyUI: Expanding Your Canvas
Outpainting isn’t just about fixing or changing,it’s about imagining beyond what’s there. The process in ComfyUI is similar to inpainting, but with a key difference: you’re telling the AI to generate new content beyond the image’s original borders.
Workflow:
- Load your image.
- Add the Outpainting node to your workflow.
- Set expansion directions and values. For example, increasing “up” by 20% means setting the value to 1.2 for that direction.
- Provide prompts for what should appear in the new areas.
- Sample, decode, and review the result.
Example 1:
You have a portrait but need a wider scene for a banner. Outpaint left and right, prompting for “soft blurred background with trees and sky.”
Example 2:
You want to extend a landscape photo to include more sky. Outpaint upwards, prompt for “blue sky with light clouds, natural lighting.”
Tips:
- Outpainting works best when prompts are consistent with the original image style.
- Expanding too much at once can lead to unrealistic results; try moderate expansions and iterate.
SDXL vs. Flux for Inpainting and Outpainting
SDXL is the recommended model for both inpainting and outpainting in ComfyUI due to its specialized checkpoints and high-quality results. Flux, while powerful in other generative tasks, currently lacks a dedicated inpainting model.
What happens if you use Flux? You can attempt inpainting using control net models, but:
- Generation is often slower.
- Results may be inconsistent,sometimes surprisingly good, other times unusable.
- Achieving smooth blends and natural textures is more challenging.
Example 1:
Trying to replace a character’s hand with Flux: Sometimes you’ll get a realistic hand, other times the shape or texture may be off.
Example 2:
Outpainting a landscape with Flux: The new areas might not match the original palette or style as closely as SDXL.
Best Practice: Use SDXL for any project where quality and consistency matter. If you want to experiment or push the boundaries, try Flux with control nets,but be prepared to iterate and troubleshoot.
Iterative Process: Embracing Experimentation
Inpainting and outpainting are not “one and done” actions. They’re iterative processes, often requiring multiple passes to achieve perfection. Factors to iterate:
- Mask shape and blur
- Denoise value
- Prompt specificity
- Random seed
Example 1:
You try to add a bird to a tree branch. Each new seed produces a different bird,some perched, some flying, some hidden. Try multiple seeds to find the best fit.
Example 2:
Fixing a complex background: If your first mask and prompt don’t blend well, adjust the mask’s edges, change the prompt, and try again.
Mindset: “With a little bit of luck, some denoise balancing, and good prompting, the only limit is your imagination.” Don’t be discouraged by imperfect first attempts,experimentation is where the magic happens.
Blending and Troubleshooting: Beyond ComfyUI
Sometimes, no matter how much you tweak your mask and denoise, a visible line or color mismatch remains. The solution? Blend your workflow with external tools like Photoshop.
Workflow:
- Pre-process the masked area in Photoshop (e.g., if you’re struggling to change a red area to white, quickly recolor it in Photoshop to a neutral tone).
- Bring the edited image back into ComfyUI and run the inpainting workflow again.
- Use Photoshop’s mask blur, healing brush, or clone stamp to fine-tune the final blend.
Example 1:
You’re trying to inpaint over a strong red color but the AI keeps producing artifacts. Recolor the area white in Photoshop, then re-inpaint in ComfyUI for a cleaner result.
Example 2:
If subtle lines persist after inpainting, use Photoshop’s “smudge” or “healing” tools for a final polish.
Tip: Photoshop’s Generative Fill is also demonstrated in the video as an alternative or complement to ComfyUI’s inpainting/outpainting,sometimes, combining both gives the most natural result.
Advanced Techniques: Mask Inversion, Multi-Pass Inpainting, and Complex Selections
Once you’re comfortable with the basics, push your creativity with advanced workflows:
- Mask Inversion: Use the invert mask option to freeze the masked area and modify the rest of the image. For example, keep the original head but generate a completely new body and environment.
- Multi-Pass Inpainting: Apply inpainting in several passes, targeting different regions or refining details with each iteration.
- Complex Selections: Combine multiple masks or use soft-edged masks for layered effects.
Example 1:
You want to change both the background and a character’s outfit. Inpaint the outfit first, then mask and inpaint the background in a second pass.
Example 2:
Creating a surreal composite: Use mask inversion to keep a subject’s face, then outpaint a dreamlike environment around them.
Common Challenges and Solutions
Even with perfect workflows, you’ll face some recurring challenges:
- Hard Edges: Increase mask blur or blend externally.
- Color Mismatch: Preprocess in Photoshop or adjust prompt/denoise.
- Unwanted Artifacts: Tweak negative prompts and try new seeds.
- Slow Generation (especially with Flux): Reduce image size or try SDXL for efficiency.
Best Practice: Keep a log of your settings and results. Over time, you’ll develop a sense for what works,and a library of prompts and mask settings that become your creative toolkit.
ComfyUI File Management: Where to Store Models and Checkpoints
Quick note for smooth operation: Always place your model checkpoint files in the “checkpoints” folder within your ComfyUI directory. This ensures ComfyUI recognizes and loads them correctly. If you download new inpainting models or experiment with different architectures, keep them organized in this folder for easy switching during workflow creation.
Tip: If ComfyUI doesn’t recognize a new model, double-check the file location and restart the program.
Practical Scenarios: Applying What You’ve Learned
Let’s bring it all together with practical, real-world scenarios:
-
Correcting a Photo Mistake:
A wedding photo has a distracting object in the background. Mask the object, use an inpainting prompt like “natural garden background,” and blend the result. Try several seeds for the most natural look. -
Creative Enhancement:
An illustration feels empty. Mask an area, prompt “a white dove flying,” and inpaint to add a new visual element. Adjust denoise for subtlety or drama. -
Outpainting for Social Media:
You want to fit a square image into a wide banner format. Outpaint left and right, prompting for “soft, blurred background with matching lighting.” -
Surreal Composites:
Keep a realistic head, invert the mask, and generate a fantasy landscape around the subject for eye-catching artwork.
Summary and Key Takeaways
You’ve covered every major theme and technique for inpainting and outpainting in ComfyUI, focused on SDXL, with honest exploration of Flux’s current state. You now know:
- What inpainting and outpainting are, and why they’re powerful creative tools.
- How to install and utilize the essential custom nodes: Inpaint Crop and Inpaint Stitch.
- The importance of dedicated inpainting model checkpoints, and where to store them.
- How to construct a robust, flexible workflow in ComfyUI, from loading your image to blending the inpainted result.
- The critical role of masking, context area, and parameter tuning (especially denoise).
- The value of prompt engineering, iteration, and embracing experimentation.
- The strengths of SDXL and the limitations (and possibilities) of Flux.
- When to blend your workflow with external tools like Photoshop for seamless results.
The real power lies in your willingness to experiment and iterate. The combination of precise control and boundless creativity makes inpainting and outpainting in ComfyUI an essential skill for anyone working with images and AI. Whether you’re fixing, enhancing, or reinventing, these workflows put the “creative” back in creative AI.
Now, open ComfyUI, pick your favorite image, and start experimenting. The only limit is your imagination.
Frequently Asked Questions
This FAQ section is designed to answer common and advanced questions related to the use of SDXL and Flux models for inpainting and outpainting within ComfyUI, focusing on practical workflow setups, troubleshooting, and best practices. Whether you’re just starting or looking to refine your techniques for professional image editing, you’ll find actionable advice and insights here.
What is inpainting and how is it used in ComfyUI?
Inpainting in ComfyUI is a technique used to modify existing images by changing or adding elements and fixing mistakes within specific areas.
It allows users to take creative control over their images, enhancing or altering them beyond the initial generation. In ComfyUI, this is achieved using custom nodes like "inpaint crop" and "inpaint stitch," which work together to isolate a selected area, process it based on prompts and settings, and then seamlessly integrate the modified section back into the original image.
What are the key custom nodes required for inpainting in ComfyUI and what do they do?
The primary custom nodes needed for inpainting in ComfyUI are the "inpaint crop" and "inpaint stitch" nodes.
The "inpaint crop" node isolates the specific area of the image that the user has selected (masked) for modification. The "inpaint stitch" node then takes the processed, cropped area and combines it back with the original image, ensuring a cohesive final output. These nodes are essential for the workflow, allowing for targeted edits without affecting the entire image.
How do you set up the inpainting workflow in ComfyUI with an SDXL model?
Setting up an inpainting workflow with an SDXL model in ComfyUI involves several steps.
Begin with a basic SDXL workflow and download an SDXL-based inpainting model checkpoint; place it in the checkpoints folder. Add an "inpaint model conditioning" node before the K sampler, connecting prompts and outputs accordingly. Instead of an empty latent image node, use a "load image" node to bring in your image. Connect to the VAE decode node, and add "inpaint crop" and "inpaint stitch" nodes. Link the image and mask outputs, and make sure the "forced size" in the inpaint crop node is set to 1024 pixels for SDXL models. This sequence enables you to isolate, process, and reintegrate modified image regions.
How is the mask editor used in ComfyUI for inpainting?
The mask editor in ComfyUI allows you to define which area of the image is affected by inpainting.
Right-click on the loaded image node and select "open in mask editor." Use the brush tool (adjust size with mouse wheel or bracket keys) to paint the area for modification,white for selection, right mouse to erase, and "clear" to reset. Once satisfied, click "save to node" to send the mask to the workflow. The precision of your selection directly impacts the results, so take care to match the mask to your desired changes.
What role does the denoise value play in inpainting results?
The denoise value controls how much the generated content in the masked area deviates from the original image.
A value of 1 gives the AI full creative control, often generating something entirely new, while lower values (like 0.5) keep more of the original details. This balance is key: higher values for dramatic changes, lower values for subtle edits. Adjusting this parameter can make the difference between a seamless fix and a radical transformation.
How can you improve inpainting results when the AI struggles to incorporate the prompt?
If the AI isn't following your prompt well, try increasing the denoise value and enlarging the mask selection.
Giving the AI more context (via the expand factor or context area) helps it understand surrounding content. Pre-coloring the masked area in an external editor with a base tone similar to your desired outcome can guide the model. Sometimes, multiple attempts with varied seeds, prompts, or iterative inpainting steps are needed for the best result.
What is outpainting in ComfyUI and how does it work?
Outpainting adds new content outside the original image boundaries, expanding the canvas.
By using an "outpainting" node, you specify which direction to expand (left, right, up, down) and by how much. The AI then generates new pixels based on your prompt, extending the existing scene. This is especially useful for broadening an image for banners, social posts, or creative storytelling visuals.
How does the "invert mask" setting in the inpaint crop node function?
The "invert mask" setting reverses your mask selection.
Instead of modifying the painted area, the workflow alters everything outside the mask. This is helpful for updating backgrounds or environments while leaving the subject untouched, or for creative effects where only part of the image needs to remain original.
Where should I place the inpainting model checkpoint file in ComfyUI?
Place the inpainting model checkpoint file in the "checkpoints" folder within your ComfyUI directory.
After downloading your SDXL inpainting model, move it to this folder to ensure ComfyUI can detect and use it in your workflows.
Why is the Empty Latent Image node not needed when using inpainting with an uploaded image?
When inpainting with an existing image, you start by loading that image directly instead of generating one from scratch.
The "load image" node replaces the need for an empty latent image, streamlining the workflow and ensuring the original content is preserved for targeted edits.
What is the function of the Inpaint Crop node and the Inpaint Stitch node in the workflow?
The Inpaint Crop node crops the selected (masked) area for processing, while the Inpaint Stitch node merges the edited region back into the original image.
This two-step approach enables precise, localized changes without altering the rest of the image, supporting both subtle fixes and creative transformations.
What is the primary purpose of inpainting in ComfyUI?
Inpainting is primarily used to modify, fix, or creatively alter specific areas of photos or illustrations.
It gives users more control over image editing,whether that's removing objects, correcting mistakes, or adding new details in a way that looks natural and intentional.
How does the Denoise value affect the outcome of inpainting?
The Denoise value determines how much change the AI is allowed to make in the masked area.
A higher denoise value introduces more variance and creativity, while a lower value preserves more of the original features. For example, setting it high can completely change a face, while setting it low will only make subtle tweaks to an object or detail.
How can I improve the blending of an inpainting result if a subtle line is visible?
Increase the "mask blur" setting in the Inpaint Crop node to soften the edges of your mask.
Blurring the transition zone between the original and inpainted areas helps to smooth out any visible lines and create a more natural blend. This is especially effective when editing portraits or organic backgrounds.
Besides changing specific elements, what else can I use inpainting for?
Inpainting is also effective for compositional changes, such as retaining a person's head but generating a new body and environment around it.
By inverting the mask, you can keep chosen features untouched while reimagining the rest of the scene,useful in scenarios like fashion, advertising, or conceptual art.
What is the key difference in using Flux models for inpainting/outpainting compared to SDXL models?
Flux models currently lack dedicated inpainting models, so control net models are used as a workaround.
This approach can sometimes slow down generation or produce less reliable results compared to SDXL’s specialized inpainting models. For high-stakes or production work, SDXL is generally the preferred option.
Why is the selection size in the mask editor important for inpainting results?
The selection size directly affects how much context the AI receives and how natural the inpainted result appears.
A small mask can yield awkward transitions or limited changes, while a larger mask provides the model with more visual information to generate coherent edits. For example, when replacing a background, masking a wider area around the subject helps the AI blend new content more effectively.
Can I use inpainting to remove unwanted objects from photos?
Yes, inpainting is highly effective for removing objects or distractions from images.
Simply mask the area you want to remove, use a prompt like "clean background," and allow the AI to fill in the region. This is commonly used in real estate photos, product images, and social media content to create a polished look.
How does prompt engineering impact inpainting results in ComfyUI?
The quality and clarity of your prompt guide the AI’s creative decisions in the masked area.
A well-phrased prompt with specific details leads to more predictable and relevant changes. For example, "add a red scarf to the woman" produces a targeted result, while a vague prompt may yield unexpected modifications. Experimenting with phrasing can help you refine the outcome.
What is the context area or expand factor in inpainting, and why does it matter?
The context area (expand factor) extends the mask to include more of the surrounding image, giving the AI more information to work with.
A larger context helps the model generate transitions that match lighting, color, and texture. This is especially important when blending new content into busy backgrounds or maintaining perspective in architectural edits.
What are common mistakes to avoid when setting up an inpainting workflow?
Avoid using mismatched model checkpoints, incorrect mask connections, or skipping essential nodes like "inpaint crop" and "inpaint stitch."
Other pitfalls include forgetting to set the forced size for SDXL models, using overly small masks, or neglecting the denoise and mask blur settings. Double-check your workflow connections and review the node properties before running a job.
How can I use inpainting for business applications?
Businesses use inpainting to streamline image editing for marketing, product catalogs, social media, and creative campaigns.
Examples include removing watermarks from stock imagery, updating product backgrounds, retouching headshots, or customizing visual assets for targeted promotions. Automating these tasks in ComfyUI can save significant time and reduce editing costs.
How do I handle color mismatches or unrealistic results in inpainting?
If the AI generates mismatched colors, try pre-coloring the masked area in an external editor with a base color close to your target result before inpainting.
Additionally, increasing the context area, refining your prompt, or running the process multiple times can improve realism. For difficult cases, consider manual touch-ups after inpainting.
Is it possible to inpaint on large images with SDXL or Flux models in ComfyUI?
Yes, but you need to adjust the forced size and be mindful of hardware limitations.
SDXL models typically work best with images sized at 1024x1024 pixels. For larger images, split your edits into sections or use tiling workflows. High-resolution inpainting requires a powerful GPU and may be slower, but it’s achievable with careful planning.
What should I do if my inpainting result is not seamless or has artifacts?
Increase the mask blur, expand the context area, refine your prompt, and try different denoise values.
Artifacts can also result from model limitations or incompatible checkpoints. Running the workflow with different random seeds or performing iterative inpainting (repeating the process on the output) often helps reduce visible seams and artifacts.
Can I use inpainting and outpainting together in a single workflow?
Yes, you can combine both techniques for advanced image edits.
For example, you might outpaint to extend a landscape and then inpaint specific elements within the new area for creative or corrective purposes. This approach is popular in digital art, advertising, and visual storytelling projects.
How do Flux models handle inpainting differently from SDXL?
Flux models use control net models to approximate inpainting since they lack dedicated inpainting checkpoints.
This workaround can result in slower processing and less consistent outputs, so expect to experiment more with prompts, denoise settings, and context area when using Flux. SDXL remains the preferred choice for high-quality, reliable inpainting.
What is the role of the inpaint model conditioning node?
This node prepares the positive and negative prompts specifically for the inpainting model, taking the mask and cropped image as input.
It ensures that prompt instructions are focused on the masked area, improving the relevance and accuracy of the inpainting. Skipping this node can lead to unpredictable results or ignored prompts.
How can I speed up inpainting or outpainting in ComfyUI?
Use optimized checkpoints, limit the image size, and reduce the number of sampling steps.
Batch processing multiple images or using lower denoise values can also reduce processing time. For large jobs, consider running tasks on a high-end GPU or cloud-based service.
Are there any limitations or challenges when using inpainting models in ComfyUI?
Common challenges include hardware requirements, model compatibility, and occasional artifacts or unnatural results.
Inpainting models are sensitive to mask size, prompt specificity, and context area. Experimentation and iterative refinements are often necessary, especially for complex edits or when using non-dedicated models like Flux.
What types of images work best for inpainting in ComfyUI?
Images with clear structure, consistent lighting, and moderate resolution (around 1024x1024 pixels) offer the best results.
Highly detailed or noisy images may require extra care with mask size and prompt tuning. For business use, professionally shot product photos, portraits, and simple backgrounds are ideal candidates.
How do I save or export my inpainting results from ComfyUI?
Connect a "save image" node at the end of your workflow to export the final output.
You can specify the file path and format (e.g., PNG, JPEG). For batch jobs, use a loop or automation node to process multiple images. The exported files can then be used in presentations, marketing materials, or further editing.
What is the role of the VAE in inpainting workflows?
The Variational Autoencoder (VAE) encodes and decodes images between pixel and latent space in the workflow.
It’s essential for converting loaded images into a format the model can process and then decoding the output for final export. Using the correct VAE for your model ensures optimal quality and color accuracy.
Can I use inpainting with complex or multiple masks in ComfyUI?
Yes, you can create intricate masks in the mask editor or repeat the inpainting process on different regions.
For overlapping or complex edits, use the mask editor to paint multiple areas in one go, or iteratively apply inpainting to each region. This allows for advanced compositing and creative control.
How can I iterate or refine an inpainting result if I'm not satisfied?
Repeat the inpainting process on the output, adjusting your mask, prompt, denoise, or context area as needed.
You can also try different random seeds, refine your prompt, or tweak mask blur settings. Iterative refinement is often the key to achieving truly seamless and realistic changes.
Can the inpainting workflow be automated for batch processing in ComfyUI?
Yes, ComfyUI supports automation for batch processing of images using loops or scripting nodes.
This is useful for businesses needing to process large sets of product images or social content at scale, saving time and ensuring consistent results across many files.
Where can I find additional custom nodes for inpainting or outpainting in ComfyUI?
Custom nodes are available through the ComfyUI community, GitHub repositories, or forums.
Always verify the compatibility and trustworthiness of third-party nodes before installation. Check the documentation for each node to understand new features or settings that may improve your workflow.
How can I troubleshoot if a custom node fails or isn’t working as expected in ComfyUI?
Double-check node installation, dependencies, and connections in your workflow.
Review error messages, update your ComfyUI installation, and consult the developer’s documentation or user forums for support. Sometimes, deleting and re-adding the node or restarting ComfyUI can resolve minor glitches.
Are there any security or privacy concerns when using inpainting models in ComfyUI?
If you’re working with sensitive or proprietary images, keep all processing local and avoid uploading data to external servers.
ComfyUI can run entirely offline, and using trusted, locally stored models helps protect your data. Always review third-party node code before use in confidential environments.
Certification
About the Certification
Transform photos and illustrations by adding, removing, or refining details with ComfyUI’s inpainting and outpainting tools. Learn step-by-step workflows, advanced masking, and prompt techniques to achieve seamless, creative edits with SDXL and Flux.
Official Certification
Upon successful completion of the "ComfyUI Course: Ep19 - SDXL & Flux Inpainting Tips with ComfyUI", you will receive a verifiable digital certificate. This certificate demonstrates your expertise in the subject matter covered in this course.
Benefits of Certification
- Enhance your professional credibility and stand out in the job market.
- Validate your skills and knowledge in a high-demand area of AI.
- Unlock new career opportunities in AI and HR technology.
- Share your achievement on your resume, LinkedIn, and other professional platforms.
How to complete your certification successfully?
To earn your certification, you’ll need to complete all video lessons, study the guide carefully, and review the FAQ. After that, you’ll be prepared to pass the certification requirements.
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