RabbetSpace is a neutral pH black plastic rabbet depth extender used on the back of wood picture frames to extend the depth of shallow rabbets. This comes in handy when doing "Spacer Framing" in ready-made frames as the rabbets are usually too shallow to accept the combined thickness of the glass, mats, spacer, and backing. RabbetSpace is easily screwed to the back of the frame and comes in 4 sizes from 1/8 inch to 1/2 inch extensions. 5ft/Stick    35ft/Bundle