Textures

When designing images, there are many cases where you may need to use a texture to fill an object. Textures are commonly used in maps and charts as an alternative to colour, which can be helpful to people with colour vision deficiencies. Many drawing software packages come with a selection of texture fills ready to use and also options that allow you to design your own.

Textures need to be selected carefully. Some textures work well for many people, but some can cause uncomfortable visual effects and illusions. Other textures can be difficult to look at for some sight conditions, or may appear as a solid colour.

Good textures

• Evenly spaced wavy textures.
• Grid-like textures that have even spacing without high contrast.
• Dotted textures that have even spaces between dots, and dots that are not too small.
• Broken diagonal line textures. The broken line breaks up the effect that can make the eye appear to jump.

Textures to avoid

• Bold textures with a heavy black and white contrast can be uncomfortable to look at, particularly those that create visual illusions. For photophobic people, textures like these can be painful to view.
• Closely spaced or strongly contrasted vertical and wavy lines can be uncomfortable for people with nystagmus, as the lines can make the eye movements seem more prominent.
• Diagonal lines are preferable to vertical lines. However, they can also be uncomfortable or disorientating to view as they can make the eye appear to jump.
• Textures with irregular sized dots can be difficult and distracting to see.
• Textures with small details can be difficult to see as the texture may appear different to some people.
• Textures with closely packed detail may appear as a solid colour to some. This could cause confusion if there are other features on a diagram that are the same colour.
• Textures with thin lines or small dots that are very close together can appear as a solid colour.

Using textures

Some textures work better in small areas and others in larger areas. Other textures should not be used together as they will be uncomfortable to see:

• Avoid using wavy line textures beside each other, as they will become confusing to see.
• Grid-like textures work best for medium to large features that need to stand out. Avoid using them for background details as they stand out too much.
• Large dotted textures are best used for details that need to stand out as opposed to background features.
• Fine dotted textures are best for background detail rather than features that need to be located.
• Diagonal textures with a broken line are effective for small to medium size features, depending on the line thickness. Finer lines work better for background, whereas bolder lines work better for main details. These textures should not be used close together.