I recently made a large Spring 1942 (with neutrals) using IL’s Supreme map file. All I can say is that it turned out very, very nice!
I had it printed on a 54x27 inch map. The material I had it printed on is generally called a “Trade Show Retractable Print” material. This is the kind that you pull out of a retractable roller similar to the white screens you use for movies or projectors. There are several variations of this material. The one that was used for my map is called “Decolit”.
The print comes out very clean. It also has an anti-curl feature. So it lays very flat on the table even when it has been rolled up after a while. In fact The Decolit also has a slight rubbery feel to it. So pieces tend not to slide around if you bump the table. This also makes it resistant to liquids. If you spill something on it, it wipes off very easily and without staining (at least with cherry coke :-D) if you wipe it quickly. But the biggest Pro for this material is that mat finish. You get virtually no glare from it, even in direct sun light.
The only real cons with this material is that it is a bit on the thin side. So you must use this on a smooth flat surface. However, I assume this really isn’t a problem for most people. The only other con is that Decolit is a bit more expensive compared to other materials. I was told that the anti-curling feature was the main reason for the added expense. This map set me back about $140 plus $13 tax. I could have had this made on banner material for almost half the price but there would have been glare issues. I’m glad I went the Decolit.
One thing I would have changes if I was able to modify the map would be to chance the color of the IPC numbers in the neutral countries from white to grey to give to show a little bit more clearly that they are neutral.