The ultimate guide to designing icons

Always keep your frame consistent and export icons out at that frame size.

a 16x16px frame
Even though the cross is different weights and sizes all the frames are 16x16px

Try and fill as much of the bounding box as possible. This helps if you have tool bars or want to align multiple icons together.

When placed together the icons feel aligned and as part of a unified set.

Stroke that sit inside the pixel will render much better than those that sit between the pixel grid.

Always use strokes at 1px (or your own scale) and inside the shape, this will reduce pixelation when exported.

Keeping strokes to the pxiel grid will reduce pixelation when exported, keeping icons looking crisp and sharp.

The shopping cart on the left is aligned, where possible, to the pixel grid, reducing the ‘pixel puke’ of none aligned strokes.

In this example of pixel aligned strokes vs center aligned strokes shows the difference on lower resolutions displays. The shopping trolley becomes barely recognisable when strokes are not pixel perfect.

One way of making sure that your icons are aligned is by manually adjusting the X and Y positions. This is especially helpful if you have pixel grid snapping on, where center aligned strokes snap to the grid and not fill the pixel.

Manually adjust the X and Y position to align strokes to the pixel grid.

Adding .5 to the X and/or Y position makes sure that your icons are aligned to pixels and not the grid.

Tweaking the X and Y position makes for crisp icons, especially on lower resolution screens.

Using this technique allows for fine-tuning of your icons to make sure that every viewer has a recognisable experience.

OK, so I’m going to slightly contradict some of the pixel alignment rules above here…

Adding fine detail, can sometime make the difference.

Adding finer detail; Sometimes icons need just a little extra detail to make the difference between a circle or a coin. I’m using a 0.5px stroke to add a little bit of detail, this helps when you have a large number of icons and icons of similar shapes. Make sure, where possible, to keep the stroke within one pixel grid and avoid the ‘pixel puke’ rasterisation on lower resolution screens.

Try and keep the strokes with in the pixel grid and not over 2 boxes.

I like my icons a little softer and introduce a small corner radius, at 16px I use the corner radius of 1px.

In Figma you can adjust each corner, starting at the top left and working clockwise.

The corner radius can be adjusted depending on the use, e.g. arrow or pointy objects should have no corner radius (unless that’s your design language).

You can adjust the individual corners by clicking the ‘corner’ icon.

To adjust the corner radius at each corner use the top right panel or select the corner that you want to adjust.

As a general rule, stroke caps are a bit painful in icons, not adding them this makes it easier to keep the strokes aligned to the pixel grid.

How stroke caps change the length of a line.

Depending on the style of icons and your preference, you can change the caps on all endpoints or individually by selecting the Edit object icon.

Much like the aligning strokes the stroke cap needs to sit within the pixel. Adding caps adds .5 pixels to the length of your line.

To accomodate this, lines with caps at both ends need to be 1px shorter than those without caps.

How stroke caps change the length of a line and can make your icon go off pixel grid.

For example, aline with a length of 26px will be 27px with caps at both ends. To make things consistent reduce the length of capped strokes by 1px.

A rounded cap stoke will is drawn at 25px in length, but actually by 26px on the pxiel grid.

You also need to adjust the X or Y position to reflect the new start point of a capped stroke. Your strokes will have to sit .5 px in to align with the pixel grid.

Always make your icon constraints set to ‘Scale’ — select all the layers in your icon and change to ‘Scale’.

Use the Constraints panel to make sure that your icons and all the layer within are set to Scale both horizontally and vertically.

This helps to scale the size when used in nested components, e.g. buttons with icons.

In this example just one of my layers isn’t set to Scale, just keeping it pinned to the top left of the frame.

Figma’s scale tool

You can manually scale an icon, using Figma, with the Scale tool (K). To note, this only helps if you’re not using nested components. Icons that are using strokes vs icons that are outlined will only scale the shape and not the stroke or corner radius.

An icon using a stroke

There are pros and cons to keeping the strokes in your icons. Keeping the stroke allows for easier editing in the future. While outlining a stroke makes corners and strokes scale wherever you use them. To outline a stroke, using Figma, SHIFT + CMD + O.

Stokes vs Outlined (filled) shapes.

Calculating the corner radius at different icon scales.

Icons work best at the power of 8. So always try and make your icon sizes divisible by 8 — this depends on what grid you’re using, if you’re using a 10×10 grid then make icons divisible by 10. For best results keep icon sizes consistent with your font sizes. For example, if you’re using a 16pt/px font then use icons divisible by 8. If you’re using a 20pt/px font then use icons divisible by 10.

How my heart icon scales up at different increments.

Icons should be scaled to a maximum of 48px, beyond that use a spot illustration.

Strokes and corner radius should always be scaled in relation to the size of the icon.

For example:

16px icon = 1px stroke
24px icon = 1.5px stroke
32px icon = 2px stroke

16px icon = 1px corner radius
24px icon = 1.5px corner radius
32px icon = 2px corner radius

Just like font weights, icons can have weights. As a rule of thumb, icons should match the font weight used near them.

Icon weights to match font weights

Again, just like normal strokes these should be scaled (K) if the icon is scaled.

Scaled icons at different weights

Using different weight icons to match the size and weight of the font.

Using variants and a few adjustments makes your icon consistent and useable in different situations.
Categorized as UX Tagged

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