I have been making a series of encaustic atc's or artist trading cards. Using small canvas boards to work on, I have also used jumbo playing cards. Its great for experimenting and trying new ideas.
I have been playing around with orange solved papers,rusting papers,burning paper,bleeding tissue papers and all that kind of thing.Then combining that with some image transfer. layering colour and text as well.
The boards are gesso coated but as I am using lots of paper to cover that it seems to work out okay and they are only usually give aways so I dont worry too much about the archival qualities of them so much.