Icon design for brands: rules that keep a set consistent

The short answer

Brand icons stay consistent when they share a grid, stroke weight, corner style, level of detail and colour rules. Write those rules down, design every icon on the same canvas, test them at small sizes, and decide early whether to draw a custom set or adapt an existing icon library.

Why icon consistency matters

Icons appear in navigation, buttons, presentations, packaging and apps. When they match, people read them quickly and the brand feels organised. When they come from different sources, with thick strokes beside thin ones and rounded corners beside sharp ones, the mismatch makes the whole interface feel unfinished.

Consistency is mostly a matter of writing down a handful of rules and applying them to every new icon, including ones added years later by someone else.

Start with a grid

Draw every icon on the same square canvas, with the same padding and keyline shapes such as a circle, square and tall and wide rectangle. These guides stop icons from looking too large or too small next to each other, because a circle and a square of the same width do not feel the same size.

Choose the base size you will design at, then check scaled versions. Many teams design at one small size and scale up, rather than the reverse.

Set the visual rules

• Stroke weight. Pick one line thickness and keep it for the whole set.
• Corners. Decide on sharp, slightly rounded or fully rounded, and apply it everywhere.
• Fill. Choose outline, solid or a mix, and say when each is used, for example solid for the active state.
• Detail. Set a limit on the number of shapes per icon so complexity stays even.
• Perspective. Use flat, front-facing shapes unless the brand style calls for something else.
• Ends and joins. Round or square line ends should match across the set.

Colour and the brand

Decide which brand colours icons may use and whether they appear in a single colour or two. Check each combination for contrast on the backgrounds where it will appear, using our guide to brand colour accessibility. Icons that carry meaning should not rely on colour alone.

If icons are used inside a mood or style that the mood board defined, keep their personality in line with it: playful and rounded for a friendly brand, precise and sharp for a technical one.

Custom set or existing library

A custom set suits a brand with a distinctive personality or a product with unusual concepts to illustrate. An existing library saves time and cost for standard needs such as arrows, search and settings. Many brands combine both: a licensed base library with custom icons for the few concepts that are unique.

If you use a library, read its licence for commercial use, modification and attribution. Check the current terms rather than relying on memory, since licences change.

Sizes, files and testing

• Test every icon at the smallest size it will appear.
• Export in a scalable format for screens, and supply raster versions where a platform requires them.
• Name files consistently so they can be found, as described in the brand asset library guide.
• Add accessible text labels in digital products, because an icon alone may be unclear to some users.
• Check each icon against a plain background and a dark background.

Keep the set growing without breaking it

Write an icon request process: a short brief, a check against the rules, and a review before the icon joins the set. Keep the source files in one place with the rules written beside them. When a team member adds an icon, they should be able to follow the rules without asking.

Add the finished icon rules to your brand guidelines with clear examples of correct and incorrect icons.

A short brief for a new icon

1. What does the icon stand for, in one plain sentence?
2. Where will it appear, and at what smallest size?
3. Which existing icons is it most similar to, so the style can match?
4. Is there a common symbol people already understand for this idea?
5. Who approves it, and by when?

Testing meaning

An icon is only useful if people understand it. Show new icons to a few people with no label and ask what they think each one does. If many guess wrongly, change the symbol or add a text label. Familiar symbols, such as a magnifying glass for search or a house for the home page, are usually safer than a clever new image.

Documenting the set

Create a one-page sheet showing the grid, the stroke weight, the corner rule and an example of a correct and an incorrect icon. Store the master file with the rules and keep it with your other assets so new designers can pick it up quickly.

Related guides

• Branding and logo design
• Brand Colour Accessibility and Contrast Basics
• Brand Asset Library: How to Organise Your Files
• What goes into a brand style guide
• How to choose fonts for your brand
• How to choose brand colours

Questions and answers

What is the best stroke weight for icons?

There is no single best value. Choose one that stays clear at your smallest size and matches the weight of your typography, then use it everywhere.

Should icons be outlined or solid?

Either works if you apply the choice consistently. Many brands use outline for the normal state and solid for the active or selected state.

Can I mix icons from different libraries?

It is best to avoid it, because differences in stroke, corners and detail make the set look mismatched. If you must, redraw the icons to one set of rules.

Do icons need text labels?

In many interfaces, yes. A label removes ambiguity and helps people using assistive technology. Use icon-only buttons only for very familiar symbols.