Since I have had some more time to play with my cards, here are my updated impressions.
Copag
7 out of 10. Had issues with warped decks and the blue ink bleeding with the first two decks that I owned, which I ended up tossing out. Second set of cards seemed to have been made differently and were holding up better, but I ended up selling them to someone I knew.
Dal Negro
Non-Acetate
6 out of 10. Well I got two decks that had the paint wearing issue. The faces AND backs wore and scratched very quickly. They also attracted grime like no other card I have. Ended up tossing them.
Desjgn
8 out of 10. I really wanted these cards to do well, but things didn't go perfectly the 2 times that I have used them. First week one card develops 3 small cracks 1/16" apart. I was able to easily get a replacement deck at no charge. The second week one card creases a corner that cannot be adequate fixed or flattened. Luckily I had 51 replacement cards from the previously damaged deck. I have not used them since however.
Fournier
9 out of 10. I would say that these are the best non-Acetate cards. Absolutely no bowing. Face paint is 99.9% intact. Only issue is one card got creased, and I cannot fully 100% "repair" it.
Kem
Acetate 9 out of 10. I really like these cards, as I have 2 decks free of manufacturing defects such as the paint scratches and off center printing. These cards seem to be the most damage resistant cards I own, with no creases or face paint wear. Only issue is that one of the decks has a slight bow that I am still working on flattening.
Modiano
Non-Acetate
6 out of 10. These cards are a lost cause to me. So many little things have gone wrong with the 10 decks I own. They are bowing up like a taco shell, the face paint slowly wears away, they hold creases and finger nail dents. I'll either give these away or toss them.
Modiano
Acetate 9 out of 10. So far these are holding up better than regular Modianos. No bowing so far, face paint holding up, and no finger nail dents. One card did get a crease in it that I cannot fully 100% "repair", but overall pretty good for the short while that I have had them. These are the only Modianos that I can recommend, and luckily they are the best looking of the whole line.
I am currently using the Fourniers, Kems, and Acetate Modianos. I would have to say that out of the group of people that play with my cards every week they hold the Modiano Acetates as there favorites, followed by the Kem and Fourniers.
