PPD Inkjet PREMIUM Iron-On White... https://www.amazon.com/dp/B004BF6BZI?ref=ppx_pop_mob_ap_share

This is the link to the material I'm using.

I'm not sure how to do the heat mask as you say. I'm a complete newbie with cricut & design space in general. I'm using my wife's stuff for this but she mostly does stickers so this isn't a process she's familiar with.