A raster image is made from a grid of coloured pixels. Photos, digital paintings, screenshots, social-media graphics and web banners are common examples. If you want to learn how to create a raster image without paying for expensive software, free editors such as Krita, GIMP, Photopea and Paint.NET provide everything needed for basic to advanced work.
This guide explains how to choose a tool, create a canvas, draw and edit with layers, manage image quality, and export a finished file. The instructions work well for students, creators, small businesses and beginners in India.
Key Takeaways
- Choose Krita or GIMP for desktop-based drawing and advanced editing.
- Use Photopea when you need a browser-based editor with PSD support.
- Paint.NET is a simple Windows option with layers, effects and multiple file formats.
- Set pixel dimensions before drawing; enlarging a small image later can reduce quality.
- Save an editable project file before exporting a PNG or JPEG.
- Use PNG for transparency and lossless graphics; use JPEG for smaller photographic files.
What Is a Raster Image?
A raster image stores visual information as pixels arranged in rows and columns. Each pixel contains colour data, and together the pixels form the complete picture. The more pixels an image has, the more detail it can generally display at its intended size.
PNG and JPEG are common distribution formats. Photopea's official documentation describes them as single-layer rectangular raster images made from a grid of pixels. When you save a layered project as PNG or JPEG, editable elements such as text and separate layers are flattened into pixels. Photopea explains raster formats and export behaviour.
Raster graphics are useful for:
- Digital paintings and illustrations
- Photographs and photo corrections
- Website images and blog graphics
- YouTube thumbnails and social posts
- Scanned documents and screenshots
- Textures, game assets and wallpapers
A raster image differs from a vector graphic. Vectors use mathematically defined paths that can be scaled without the same pixelation concerns. Logos and icons may be better created as vectors, while detailed artwork and photographs are usually better suited to raster editing.
Choose a Free Raster Editor
The best application depends on your device, experience and the type of image you want to make.
| Tool | Best for | Key considerations |
|---|---|---|
| Krita | Digital painting, concept art and illustrations | Supports custom dimensions, colour models, bit depth, resolution and layers in its New Document dialog. Krita documentation |
| GIMP | Photo editing, compositing and general graphics | Its New Image dialog supports RGB or grayscale images and warns that large, high-density files require more memory. GIMP documentation |
| Photopea | Browser-based editing and PSD workflows | Runs in a web browser and exports PNG, JPG, SVG, PDF and other formats. Photopea documentation |
| Paint.NET | Straightforward Windows editing | Paint.NET 5 supports layers, transparency, unlimited history and formats including PDN, PNG and JPEG. It requires Windows 10 or later. Paint.NET features |
For a beginner using a modest laptop, start with Photopea or Paint.NET. Choose Krita if drawing is your priority. GIMP is a strong all-purpose choice when you need detailed selections, masks, filters and compositing.
Download desktop software only from its official website. If you use Photopea, access the official domain and avoid uploading confidential documents on a shared or public computer.
Plan the Image Before Creating It
A few minutes of planning prevents common quality problems.
Define the purpose
Decide where the image will be used:
- Screen display, website or social media
- Printing
- Presentation or school project
- Photo editing
- Digital painting
- Transparent logo-like artwork
The intended use determines the canvas size, colour mode, background and export format.
Select pixel dimensions
Enter the final width and height in pixels when creating the document. For example, you might create a 1,920 × 1,080 canvas for a widescreen digital graphic or a 1,200 × 1,200 canvas for a square design.
Do not create a tiny image and plan to enlarge it later. Upscaling cannot restore details that were never captured. If your computer has limited RAM, avoid unnecessarily huge canvases because large files can slow brushes, filters and saving.
Decide on colour and background
Use RGB for screens and most online graphics. Choose grayscale only when the final image is intended to contain shades of grey. For artwork that needs a cut-out effect, create a transparent background if your editor supports it.
For print work, confirm the printer or publishing service's requirements before choosing a colour profile or resolution. Screen dimensions and print dimensions are not interchangeable.
Create a New Raster Document
The menu names vary slightly, but the workflow is similar in most editors.
- Open the application or Photopea.
- Select File > New. In Krita, you can also press
Ctrl + N; the official dialog lets you set dimensions, orientation, colour model, bit depth, resolution, background and layers. Krita's New Document guide - Enter the required width and height in pixels.
- Select RGB and a suitable bit depth unless your project has specialist requirements.
- Set the background to white, a chosen colour or transparency.
- Give the document a descriptive name, such as
kerala-food-poster. - Create the canvas.
At this stage, you have a blank raster document. Save the editable project immediately. Krita uses .kra, GIMP uses .xcf, Paint.NET uses .pdn, and Photopea commonly uses .psd for documents that preserve structure.
Build the Image With Layers
Layers are separate surfaces stacked above one another. They let you edit one part of an image without permanently changing everything below it.
A practical layer structure could be:
- Background
- Sketch or layout
- Main shapes
- Shadows and highlights
- Text
- Colour adjustments
Create a new layer for major elements. Name layers clearly, lock finished layers when appropriate and keep the background separate from the subject.
Draw or paint
Select a brush, pencil, shape or fill tool. Adjust size, opacity and hardness to control the result. A mouse is sufficient for simple graphics; a pressure-sensitive tablet can make painting more natural.
Use a low-opacity sketch layer to block in proportions before adding colour. Zoom in for detail, then zoom out regularly to check the overall composition.
Add shapes and text
Rectangle, ellipse, line and selection tools are useful for posters, diagrams and thumbnails. Keep text on its own layer while working. If you export to a flattened format, the lettering becomes pixels and may no longer be editable as text.
Use high contrast between text and its background, and check the design at the approximate size at which people will view it on a phone.
Use selections and masks carefully
Selections restrict edits to a defined area. Masks hide or reveal portions of a layer without deleting the original pixels. They are useful for replacing backgrounds, creating soft edges and applying adjustments non-destructively.
Keep a duplicate of important layers before major transformations or filters. This makes it easier to compare versions and recover from mistakes.
Improve Quality Before Exporting
Before you export, inspect the image at 100% zoom and at its final viewing size.
Check for:
- Jagged edges caused by drawing at an unsuitable size
- Accidental transparent or empty areas
- Spelling and alignment errors
- Unwanted brush marks
- Colour shifts between layers
- Text too close to the edge
- Excessive noise or sharpening
- A file size that is difficult to upload over a slower connection
If you need to resize, decide whether you are changing the canvas or the artwork. Changing canvas size adds or removes surrounding space; scaling the image changes the pixel dimensions of its contents. Make a backup before applying either operation.
For Indian-language designs, verify Devanagari, Bengali, Tamil, Telugu or other regional scripts in the final exported file. Some fonts may not be embedded or available on another device, so rasterising text can improve consistency when editability is no longer required.
Save and Export the Finished Raster Image
Save two versions:
- An editable project file with layers.
- A distribution file such as PNG or JPEG.
In Krita, File > Export provides formats that may not preserve the full editable document structure. Krita's File Menu reference distinguishes saving the working document from exporting an additional format.
Choose PNG when:
- You need transparent areas
- The image contains flat colours, text or sharp edges
- You want lossless compression
- You are exporting screenshots, illustrations or interface graphics
Choose JPEG when:
- The image is photographic
- Transparency is unnecessary
- A smaller file is more important than maximum editing quality
- You can accept some compression
JPEG quality settings involve a size-versus-detail trade-off. Export a test copy, inspect fine details and avoid repeatedly opening and resaving the same JPEG, because repeated lossy compression can degrade it.
Photopea uses File > Export As for formats such as PNG and JPG and allows output dimensions to be entered during export. See Photopea's official saving guide.
After exporting, open the file outside the editor. Check its dimensions, transparency, colours and appearance on both a computer and a phone when the image is intended for mobile viewing.
Common Mistakes to Avoid
Starting with the wrong size
A small canvas limits detail. Create the image at the largest practical final size, while considering your computer's memory and performance.
Flattening too early
Flattening merges layers and makes individual edits harder. Keep the layered project until the work is approved and backed up.
Confusing DPI with pixel dimensions
DPI or PPI affects print scaling, but pixel dimensions determine how much digital image data exists. A high DPI value does not magically add detail to a low-resolution image.
Exporting only the project file
A .kra, .xcf, .pdn or .psd file may not open in ordinary photo viewers. Export a PNG or JPEG for sharing, uploading or publishing.
Ignoring colour profiles
An image can look different on another screen or application if colour management is inconsistent. For ordinary web graphics, use a standard RGB workflow and review the exported file in a browser.
Using unlicensed assets
Free software does not automatically make downloaded photos, fonts or clip art free to use. Check the licence for every external asset, especially for commercial work.
Frequently Asked Questions
Can I create a raster image without installing software?
Yes. Photopea runs in a modern web browser and can create, edit and export raster documents. It is convenient on shared computers, but avoid placing sensitive files in online tools unless you understand their privacy and storage practices.
Which free tool is easiest for beginners?
Paint.NET is straightforward for Windows users who need basic drawing, layers and photo adjustments. Photopea is a practical browser option. Krita is often the better starting point for digital painting, while GIMP suits broader image-editing workflows.
Should I save my image as PNG or JPEG?
Use PNG for transparency, text, screenshots and graphics with sharp edges. Use JPEG for photographs and situations where a smaller file is useful. Keep the editable project file separately in the application's native format.
Why does my raster image look blurry after resizing?
The original image may not contain enough pixels for the new size. Enlarging a raster image requires interpolation, which estimates missing pixels but cannot recreate lost detail. Start with suitable dimensions and export at the intended display size.
Can I edit text after exporting to PNG?
Usually not as editable text. In a PNG, letters are stored as pixels. Keep the layered project file if you expect to change wording, font, colour or placement later.
Conclusion
Learning how to create a raster image is straightforward with free software. Choose a tool that matches your workflow, set the correct pixel dimensions, work on organised layers and save an editable project before exporting. Krita, GIMP, Photopea and Paint.NET cover drawing, photo editing and everyday design needs without a subscription.
Start with a small project such as a festival poster, product announcement or digital illustration. Export both PNG and JPEG test copies, inspect them on the devices your audience uses and keep your layered source file safely backed up.