The foamcore I use (X-Acto brand) is 20" x 30", so I doubt it's a Canada/US thing. Maybe just a brand-name thing?

Hmmm...

I have looked at the following vendors online:

Discount Art Supplies
Pearl
Utrecht Art Supplies
OfficeMax
DiscountOfficeSupplies.com
BuyOnlineNow.com office supply superstore
Office Depot
Staples
Dick Blick Art Materials
DocuMounts
Shopping.compare office products
MasterGraphics

...and I have yet to find one that sells 22x28"!

Sure, I didn't look too much in depth on each of those, but it shouldn't take any real digging if that was a popular format. 20x30" does seem to be the standard overall (oh, and most of the time, it seems to be called "foamboard" rather than "foam core").

Not sure where that 22x28" size would come from, actually. It's not a metric size, or even conveniently roundable to centimeters (56x71 cm?). The only clue is that 22 is twice teh length of a "letter" sized piece of paper. But then 22x15.5 would make more sense - that'd be exactly six letter-sized sheets.

Must be some weird canadian thing.


PS: it would be very useful if some of our European brethren (and/or sistren) could check on the most common size outside the US. Do they actually use something like A1 for foamboard (59.4×84.1cm), or do they stick with something a little "rounder", ISO be damned (50x75cm would be
awfully close to 20x30")?

I have used the folding "display boards" - that gives me the one full sheet, just a bit larger if I recall, and two half-sheets if I cut them off, or I can glue the floor tiles to the back, fold it out and use it as a master board. These are the 3-section boards used a lot for school fair projects and stuff. I had a bunch of used ones I cut up for my foam core - cant get much cheaper than free.

Here is the Quill site item I was thinking of above - it is longer, and just as wide before the folds.

http://www05.quillcorp.com/Catalog/Brow ... r=SHWSB36K

Hmmm, yes, when I copied from the address bar, it sure didnt look that long. Well, at least it all copied in as a hot link, not like when I place one on a Yahoo group and it gets trunkated into seperate unrelated parts.