This from Art MoCo:
No standing on the corner, chewing bubblegum for Jason Kronenwald, the Toronto artist who creates pop cultured portraits out of masticated gum and plywood. He leaves the chewing to other, more eager mouths, freeing himself up for the forty to fifty hours necessary for each portrait. No paints or dyes are used: all colour mixing takes place behind closed mouths and the only tools needed for the application of the medium, other than a Swiss Army knife and a plastic roller, are fingers and thumbs. The final product is sealed in epoxy resin.