Most "swaps" I make and receive, are similar.
Cardboard or best available.
Most stamps are used.
From my dealer, I get "MARGA CIPTA"
tough, and strong as. You could probably run over it in a truck.
Price I have no idea.
Sheesh! I just realised after Googling, this is acrylic plastic
sandwiched between paper.
I thought it was hard pressed paper.
Question remains, would you have paid the extra cost, and shipping
if this material was used?
Note this is quarter inch, not 2mm