Works best with same size images (with transparency or not).
Smaller images will be centered.

To generate a fading spray enable mipmaps, load a main picture,
and then choose another picture under a mipmap of choice.

To generate an animated spray select multiple images in the file browser.
The frames are displayed in the same order as they appear in the file browser,
and each one lasts for 0.2s. Animated gifs and videos are also supported.

To download final spray click "Save as VTF".

Transparency is broken in Linux version of TF2 when using DXT1. Use DXT5 instead!
Generate Mipmaps
Scale to fit
Use single image for animation

Image Encode settings:

Sampling Method:
Use dithering
Compression quality: