I know that Unity does its own compression on imported textures, but what about textures that are not compressed? Like files that are set to ARGB 32 bit format? Does it matter if I save the files in TIF or PNG format? PNG files tend to be smaller, but what about after they are imported into Unity? Is there a “best” or most efficient format for textures?
The best format for textures is something not lossy-compressed (i.e., don’t use JPG), and is most convenient to work with, which typically means PSD, since you can keep the files with layers and so on and don’t need to export anything. The source format is not used in any way in a build, under any circumstances. (Unless you load images yourself using the WWW class or whatever, but that’s a different topic.)
–Eric
Agreed, try use .psd where possible.