Feed The Beast Wiki:Image uploading guideline

Item images
All grid icons for items and blocks now use the tilesheet system. As such there is now a new procedure to upload such images.
 * Obtain as many images as possible directly from the mod's assets.
 * For 3D rendered blocks, grab a screenshot and use a program like Gimp to crop it down to size and remove the background.
 * Name each image exactly as it is in game. For example, if you are adding a texture for "4xIns. Garbage (blue)" then the image must be named "4xIns. Garbage (blue).png".
 * Stick all the images into a folder with the name of the mod they are from.
 * Put that folder in an archive, upload it, and send it to.