Translations:FAQ/31/en

The game wants to give you and the image designer the best possible experience, so it specifies the dimensions of the image's appearance so that the designer can be consistent in his creation. In Teeworlds, the grid map is made up of small 16*16 images, so the length and width of the image needs to be divisible by 16 in order to render successfully, otherwise there will be what is called "texture/pixel bleeding". You can search for yourself to learn more.