PEAZIP THEMES
PeaZip 7+ version accepts as icon sources arbitrarily sized graphic saved as 32 bit or 8 bit PNG with transparency.
Icons will be scaled at runtime to be rendered fitting system's icon size (or approximate size that can be efficiently rendered), up to 10x zoom - in example a small icon can be rendered ranging from 16px to 160px.

MAIN BOX THEME
Main Box theme is a variant of Main theme providing archive icons as cubic boxes.
Please note that to modify system icons for archive file types and context menu items you need to download a system icons pack and follow system specific instructions.
Graphic is saved as 32 bit PNG with transparence.
Folder 16 contains 16px icons zoomed x3 (48px)
Folder 32 contains 32px icons zoomed x3 (96px)
Folder 48 contains non zoomed 48px icons
Folder 96 contains non zoomed 96px icons