Thin low weight paper

[4lester]

I am trying to locate a source for 16# or 50gsm paper that is on a 13" roll or 12" x 24" sheets. I have been using automotive masking paper but it is coated with something that is preventing the ink (HP 920) from becoming water proof.

The paper/graphics are applied to styro foam shapes with white glue/water mix which bonds it to the foam and shrinks the paper tight.

Thanks for your help.