The inks plastisol are not suitable at all for Polypropylene, because they dry only at 160°C, and this temperature damns the polypropylene.
The ink Seriprop, instead, drys at the room temperature.
In addition, the ink Seriprop doesn't need any varnish over.
You can find all the Seriprop inks at this address: http://www.cplfabbrika.com/seriprop-quasar.html
The cleaners that you need for this ink are:
290.15 (normal) and 290.23 (slow).
If you like, you can make an order by e-mail.
The cost of shipping for a small box (these products are inflammable) is euro 45,00, from our head office (Albissola - Savona - Italy) to Nice.
Maybe is cheaper for you to come here and get the box: you will be welcome. (It's 130 Km only).
If you would like any further information or help, please do not hesitate to contact me again.
Best regards

This is Franco Ratto,