auto-generate-trackmania²-stickers.sh

for i in * ; do
	mkdir -p Stickers/$i
	convert $i -background transparent -gravity center -extent 110% -auto-orient Stickers/$i/Sticker.tga
	convert $i -resize 64x64\! -define dds:compression=dxt1 -define dds:mipmaps=6 Stickers/$i/Icon.dds
done

This is just for reference—replace * should you desire. The most public guide, seemingly endorsed by Nadeo, implies this to be a much more complicated procedure than it actually is. convert in my Linux distribution is an alias for ImageMagick, being the only dependency required.

Assuming you launch via TM² Stadium(and are in fact using this in tandem with Steam on Linux), the directory to drop generated stickers (each folder remaining separate) in is: ~/.steam/steam/steamapps/compatdata/232910/pfx/dosdevices/c:/users/steamuser/Documents/Maniaplanet/Media/Painter/Stickers

Important

The Stickers/ directory will not exist by default—just create it. This is true of all platforms.