Non-Woven Polypropylene Bags are not difficult to get plastisol inks to stick to if the ink film is fully cured. When you add nylon catalyst to regular cure temp plastisol inks, you can reduce your oven temp. down to 300F or so, and even if the ink film is not fully cured, the catalyst will continue to cross link to the nylon, polyprolylene bag, or any other temperature sensitive material and eventually fully cure in a few days. True low cure plastisol inks like our ELT Series that cure all the way down in the 250-260F range and can be printed straight out of the can on these polypropylene bags without any cure or adhesion issues. As for the Nazdar NB72, I have never sampled that particular catalyst, but I would think it would perform the same as the IC Catalyst for this application.