The mat Prim played on, and then recommended twice.
Miss Mahjong's Canopy Mat first appeared in Letter 3: a tropical love letter in natural rubber, a lush canopy of banana leaves inspired by the Martinique print, the kind of mat that turns a card table into a destination. For something bolder, Prim paired the Miss Cowgirl tile set with the Lasso Mat.
By Letter 8 Prim had played on the Canopy Mat herself and could speak to it firsthand: heavy, cushioned, exactly the right size for a table of four, with a soft surface that holds the tiles in place without sliding. She called it the best all purpose competitive mat on the market.
Written from what the letter said. Read both letters for the whole of it.