7 Mesh 3" Squares 10 Packa Plastic Canvas Item by Cousins

The first time I ordered the 7 mesh 3" square 10 pack plastic canvas on 01/13/2015 I was very happy with the stiffness of them. Then I believe I placed another order later for one more 10 pack and they were more flimsy. I wasn't happy with them. I'm making baby alphabet blocks with them and when I went to put them together the last packet I bought wanted to bend and not stay square. I'm hoping that was just a bad batch. I'm wanting to make another set of baby blocks and have been looking for a stiff 3" square plastic canvas, but haven't been successful. I can only find the one company (Darice) that makes them. That is what I ordered on 01/13/2015 sku #052371, and the squares were stiff enough. The second time when I ordered 1 more pack they were still from Darice, but more flimsy. Can you tell me if they've changed, or if there is something more stiff.