Comprehensive Guide to Using Petalica Paint for AI-Powered Sketch Colorization

Petalica Paint offers a streamlined way to transform black-and-white sketches into vibrant, colorful illustrations through AI technology.

Previously known as PaintsChainer, this tool is a resource for artists looking to quickly add color to their line art.

The automatic colorization process is user-friendly, and requires minimal input while still providing a lot of customization options.

This tutorial walks you through the entire process of using Petalica Paint, from uploading your sketch to downloading the finished artwork.

Understanding Petalica Paint’s Capabilities

Petalica Paint use artificial intelligence to analyze black-and-white line drawings and automatically apply colors that complement the artwork’s style and content.

The service is currently operated by pixiv Inc. and is available free of charge without even requiring registration or installation.

Petalica Paint is able to intelligently interpret sketch lines and apply appropriate colors, which saves artists significant time in the coloring process.

The tool offers three distinct colorization styles:

Tanpopo creates soft, gentle colorization
Satsuki offers more vibrant results
Canna specializes in realistic coloring with enhanced shading and lighting effects

Beyond simple colorization, Petalica Paint includes features for adding color hints to guide the AI and a sketch simplification tool that helps refine rough strokes into cleaner lines.

The service is fully integrated with pixiv Sketch, though it can be used independently through the Petalica website.

Accessing and Navigating Petalica Paint

To begin using Petalica Paint, open your web browser and navigate to the official website at petalica.com.

When you first access the site, take a moment to familiarize yourself with the layout.
The interface is designed to be intuitive with a clean layout that keeps the focus on your artwork.
The main screen presents you with two primary options: “Upload” to add your own sketch or “Paint a sample image” if you want to experiment with the tool’s capabilities using pre-loaded examples.
The navigation bar at the top of the page provides access to additional features and information, including the “How to” section that contains helpful guidance on using the various tools available within Petalica Paint.
The workspace is divided into two main sections: the left side where you’ll add color hints and make adjustments to your sketch, and the right side where you’ll see the colorized result update in real-time.
The tool palette containing colors and brush options is located on the left side of the screen, while style selection controls appear near the top of the interface1.

This straightforward organization makes the colorization process easy even to first-time users.

Uploading and Preparing Your Sketch

The first step in using Petalica Paint is uploading your black-and-white line drawing.

Click on the “Upload” button in the navigation bar to open the file selection dialog.
Select your sketch file from your computer—the tool accepts common image formats like PNG and JPG.

For best results, ensure your sketch has clear, well-defined lines with good contrast against the background. If your lines are too light or blurry, the AI may have difficulty interpreting them correctly.

Once your image is uploaded, Petalica Paint will automatically begin the colorization process using the default style.

This initial automatic colorization serves as a starting point that you can refine further. If you’re not satisfied with the initial result, don’t worry—you’ll have plenty of options to customize the colorization.

Selecting and Applying Colorization Styles

After uploading your sketch, you can experiment with different colorization styles to find the one that best suits your artistic vision.

To switch between styles, simply click on your preferred option in the style selection area of the interface.
The colorization will update automatically to reflect your choice, allowing you to quickly compare the different visual effects each style creates.

Take time to experiment with all three styles, as each one interprets your sketch differently and may reveal interesting possibilities you hadn’t considered.

Remember that these style changes affect the entire image, providing a foundation that you can further refine with color hints in the next step.

Adding Color Hints for Customized Results

While Petalica Paint’s automatic colorization is impressive, you can achieve more personalized results by adding color hints to guide the AI. Color hints are particularly useful when you have specific colors in mind for certain elements of your illustration or when the automatic colorization doesn’t match your vision.

To add color hints, use the color palette on the left side of the interface to select your desired color, then paint directly onto your sketch in the left canvas.

When applying color hints, you don’t need to meticulously color the entire area—just a small patch of color is sufficient to guide the AI. For example, if you want a character’s shirt to be blue, simply add a blue hint within the shirt area. The AI will interpret your hint and extend that color appropriately throughout the region.

For best results, place color hints in strategic locations that define key elements of your illustration. You might add hints for skin tones, hair color, clothing, background elements, and any object with a distinctive color.

After adding your color hints, the colorization will update to incorporate your guidance. If “Auto Refresh” is enabled (indicated by an icon in the interface), the colorized result will update automatically as you add hints.

If not, click the “Colorize” button to apply your changes.

Using the Sketch Simplification Feature

Petalica Paint offers a powerful “Sketch Simplification” feature that helps refine rough sketches into cleaner line art. This can be particularly useful if your original sketch has messy lines, smudges, or unnecessary details that you’d like to clean up before colorization. To access this feature, switch to the “Line” art edit mode using the mode selector in the interface.

The sketch simplification tool offers two distinct styles: “Panda” and “Shirokuma”. Each style processes your sketch differently, with variations in how aggressively it simplifies and smooths the lines. Panda tends to preserve more detail while still cleaning up the sketch, while Shirokuma creates a more streamlined result with smoother, more simplified lines. When using sketch simplification, you’ll see a preview of how your simplified sketch will look. If you’re satisfied with the result, you can apply the simplification and then proceed with colorization. This two-step approach—first simplifying the sketch, then adding color—often produces more polished final illustrations, especially when working from rough or sketchy original artwork.

Fine-tuning and Adjusting Your Colorized Image

After applying your preferred style and adding color hints, you may want to make further adjustments to perfect your colorized illustration. Petalica Paint allows you to continue adding and modifying color hints until you achieve the desired result. If certain areas still don’t look right, try adding more specific color hints with different colors or adjusting the placement of existing hints.

For more nuanced colorization, consider using multiple related colors to create depth and dimension. For example, instead of using a single blue for a character’s clothing, you might use a lighter blue on areas that would catch light and a darker blue for shadowed areas. This approach helps the AI create more realistic shading and highlights. You can also experiment with the brush size when adding color hints, using a smaller brush for precise details and a larger brush for broader areas. Remember that the goal is not to completely color the image yourself, but rather to provide enough guidance for the AI to understand your intent. With each adjustment, the colorized result will update, allowing you to iteratively refine your illustration until you’re satisfied with the outcome.

Finalizing and Downloading Your Artwork

Once you’re satisfied with the colorization of your sketch, it’s time to finalize and download your artwork. If you’ve been making several adjustments, take a moment to review the entire image for consistency and any areas that might need final touches. Add any last color hints to perfect the details, and ensure the overall color scheme achieves your artistic vision.

When your colorized illustration looks complete, click the “Download” button to save the image to your device110. Petalica Paint will generate a high-quality version of your colorized artwork that preserves the details of your original sketch while incorporating all the color information. The downloaded image can be used for various purposes, including personal projects, social media sharing, or further editing in other art software. If you’re using Petalica Paint within the pixiv Sketch environment, you’ll have the option to apply the colorized result to your canvas by clicking “OK” or the checkmark button, depending on whether you’re using the browser version or the mobile app.

Using Petalica Paint with pixiv Sketch

Petalica Paint is seamlessly integrated with pixiv Sketch, offering additional functionality when used within this creative platform. The integration process differs slightly between the browser version and the mobile app versions (iOS and Android). In the browser version of pixiv Sketch, you can access Petalica Paint by either drawing an illustration directly via Draw mode or by creating a canvas from an image. Click the “Colorize” button to start the automatic coloring mode, then select your preferred colorization style from the three available options.

On the mobile app versions (iOS and Android), tap the “…” button, then tap the Colorize button to start AI coloring. This opens the AI coloring editor where you can review the colorization and make adjustments using the Color Hint feature. After assigning your colors, tap “Apply” to update the image. When you’re satisfied with the result, tap the checkmark in the top right to apply the changes to your canvas. The integration with pixiv Sketch allows for a seamless workflow, enabling you to create, colorize, and share your artwork all within a single platform. This integrated approach is particularly beneficial for artists who regularly use pixiv Sketch as part of their creative process.

Maximizing Your Results with Petalica Paint

To achieve the best possible results with Petalica Paint, consider implementing several strategies based on user experiences. First, the quality of your initial sketch significantly impacts the colorization outcome. Clean, well-defined lines with good contrast against the background typically yield better results than sketchy or faint lines. If your original sketch is rough, consider using the sketch simplification feature before colorization to refine the lines.

When adding color hints, think strategically about color theory and lighting. For natural-looking results, add skin tones to characters, appropriate colors for clothing and objects, and consider the overall color harmony of your illustration. For areas with dramatic lighting, add hints that reflect both the base color and how that color might appear in highlights and shadows. The addition of even subtle color variation can dramatically improve the depth and realism of the final image.

Remember that Petalica Paint works best as a collaborative tool between you and the AI rather than a completely automated solution. The more thoughtful guidance you provide through color hints, the better the AI can interpret your artistic intent. With practice, you’ll develop an intuitive understanding of how to guide the AI effectively, resulting in faster workflows and more satisfying results for your digital artwork.

Conclusion: Embracing the Creative Potential of AI Colorization

Petalica Paint represents an excellent example of how artificial intelligence can enhance rather than replace creative processes. By automating the time-consuming aspects of colorization while still allowing for artistic input, this tool empowers artists to focus more on creative decisions and less on technical execution. Whether you’re a professional illustrator looking to streamline your workflow, a hobbyist experimenting with digital art, or a student learning about color theory, Petalica Paint offers an accessible entry point into the world of digital colorization.

The combination of automatic colorization with user-guided refinement creates a powerful synergy between human creativity and machine efficiency. As you become more familiar with Petalica Paint, you’ll discover how to leverage its features to achieve increasingly sophisticated results that align with your personal artistic style. Remember that like any creative tool, mastery comes through experimentation and practice. Don’t be afraid to try different approaches, styles, and color combinations as you explore the possibilities this innovative tool has to offer for your artistic journey.

Citations:

Answer from Perplexity: pplx.ai/share