I use rubber cement to glue the leather to old x-ray film, or cresent illustration board.(depends on what I'm tooling), but after I'm done tooling, I remove the substrate and use a piece of crepe rubber to remove the excess tack left by the rubber cement. works like a charm. try the crepe rubber (found at hobby lobby or michael's, etc...) to try and remove the tack from your current projects, and see if it works.