Hi, I'm no expert, but i think it depends on the technology you used to print the copy with, I think this technique will work if you used a photocopier or laser printer, but not if you used an inkjet printer, as the ink on an inkjet doesn't rely on heat to set.
I have an inkjet printer/scanner/copier, so I tend ot copy the parts needed and glue them to the wood, then cut out when the glue is dry. Hope this helps.
Ricky