Step 1: Bin bag foundation
Duct tape the plastic to your work bench so that it is lightly tensioned.
Then stretch alternate colour strips of duct tape across the plastic as shown in the photo.
Make sure that the edges of the tape are as close as possible without overlapping.
Step 2: Slice'n'dice
Then using a ruler and a sharp craft knife slice the strips across the so that you have separate strips of alternate colour tape.
You should end up with 8 strips.
Step 3: Shuffle the deck
Step 4: As if by magic
Necessary usage of another material other than duct tape... Magic tape the internal edges and across the strips for strength.
Add some strips of a third colour of tape to either end so that the board is rectangular - about ten percent longer than it is wide. 45cm by 55cm is tournament backgammon size so if you're picky then this is your target size.
Step 5: Flip reverse it
Tape it back to the workbench this with the underside face up.