Illustration Packs: Customizing Without Losing Cohesion

Illustration packs are a time-saving resource for websites, presentations, social posts and product interfaces. A good pack gives you a set of images that share a style, so your project looks unified. The challenge comes when you want to make them your own. Change too little and your work looks generic; change too much and the set falls apart. This guide shows how to customize illustrations thoughtfully while keeping them cohesive.

Start with the license

Before editing anything, read the terms. Some licenses allow modification, others permit use only as supplied, and some restrict certain types of products or require credit. Customizing a pack in a way the license does not permit can create problems later, especially in client work. If you are unsure how to interpret the language, our guide to reading a design asset license explains the common clauses and what they mean.

Keep a record of where each pack came from, the license terms and the date you downloaded it. A simple note stored with the project files can save a great deal of trouble if questions arise.

Know what makes the pack cohesive

Before changing a single color, study the set and identify what holds it together. Typically these elements are shared across the whole pack:

• Color palette: a limited set of hues used consistently
• Line weight: the thickness of outlines, or the absence of outlines
• Shape language: rounded or angular forms, simple or detailed
• Perspective and proportions: how characters, objects and scenes are drawn
• Level of detail: minimal, moderate or richly rendered

When customizing, try to change only one or two of these at a time. If you adjust colors, keep line weight and shape language intact.

Recolor with a system

The simplest and most effective customization is a color swap. Rather than recoloring each illustration individually, map the original palette to your brand palette once and apply the mapping across the set. Vector files make this easier, since colors are stored as editable values. If you need help creating or refining a palette, see our practical guide to building a color palette from scratch.

Pay attention to contrast. A color swap that works for one illustration might make another harder to read. Check light and dark combinations, and keep skin tones, if present, respectful and varied.

Keep strokes and scale consistent

If you place illustrations at different sizes on the same page, outlines may appear thicker or thinner relative to each other. Where possible, scale artwork so that stroke widths look consistent, or convert strokes to a uniform value before exporting. When mixing illustrations from the pack with icons or other graphics, use the same visual weight to avoid a patchwork look.

Mixing packs: handle with care

Combining illustrations from several packs is tempting, but styles rarely match. Differences in line weight, perspective and color can make a layout feel disjointed. If you must mix sources, unify them with a shared color palette, similar levels of detail and consistent placement. In many cases, it is easier and better to stay with a single pack and use its pieces creatively.

Add personal touches carefully

Small additions can give the set a distinct voice without breaking cohesion:

1. Add a recurring accent color or shape across scenes.
2. Place illustrations inside consistent frames or background shapes.
3. Use a unified treatment for shadows and highlights.
4. Pair the illustrations with typography that echoes their personality.

Avoid adding elements that clash with the pack's style, such as realistic photographs, heavy gradients or detailed textures, unless the pack already uses them.

Choose the right format

If you plan to resize or recolor, vector formats are the most flexible. Raster files are fine for fixed-size uses but harder to edit. Our explainer on vector vs raster graphics gives a clear overview of when each format makes sense. Always keep an unedited copy of the original pack so you can return to the source if you need to start over.

Test in context

Place the customized illustrations in a real layout, such as a landing page mockup or slide, and look at them at actual size. Check that they remain legible, consistent with surrounding content and appropriate for the audience. Ask a colleague or friend for a quick reaction; fresh eyes often notice inconsistencies you have stopped seeing.

Frequently asked questions

Can I change the characters in an illustration pack? Only if the license allows modification. Even then, keep alterations respectful and consistent with the pack's style.

Is it better to recolor in the original file or after export? Recoloring in the source vector file is usually cleaner and preserves quality, while editing after export is more limited.

How many illustrations from one pack should I use in a single layout? Use only what supports the message. A few well-chosen images often work better than filling every space.