21.
I used a cut out bottom of a plastic plate to texture the paste.
Apply some corn flour on both sides of the paste. If the paste is very soft and sticky you can leave it for a moment to dry from both sides. Place the paste on the plastic. Roll with a rolling pin. Try to use the same pressure throughout the whole piece. Don't roll many times back and forth. Roll just one time from one side to the other.
Peel the paste gently from the plastic being careful not to stretch it.