scratchboard

[ skrach-bawrd, -bohrd ]
/ ˈskrætʃˌbɔrd, -ˌboʊrd /

noun

a cardboard coated with impermeable white clay and covered by a layer of ink that is scratched or scraped in patterns revealing the white surface below.
Also called scratch·card, scraperboard.

Origin of scratchboard

First recorded in 1925–30; scratch + board

British Dictionary definitions for scratchcard

scratchcard
/ (ˈskrætʃˌkɑːd) /

noun

a ticket that reveals whether or not the holder is eligible for a prize when the surface is removed by scratching