I have a fairly good size tear on a leather chair ("T shaped" 2" x 1.5"). I first attempted a practice trial on the sample piece of leather provided in the kit. I created a square hole about .5" x .5". I followed the directions exactly as described in the instructions. When it came time to cure the repair compound with the heat tool, it did not cure, remained tacky. As the instructions state, repeat the curing step if compound is tacky. I repeated the step 6 times without the compound ever curing. I would like to note that I'm a manufacturing engineer that one of my biggest assets is attention to details. This product may work on very small rips and tears only.