I know I can go down to my local Joann Fabrics and buy foam for a banquette I'm making, but I don't think the quality is very good. Where on line can I buy a good dense 4 inch thick foam?
Miamicorp.com. Rochfordsupply.com both cater to the retail market without setting up a commercial account
You're quite right about JoAnn's foam. As for buying online "by the slice", You might check out this one:
http://www.foambymail.com/foam-types-for-seats-and-cushions.html
They offer free shipping on orders over $75. I haven't checked their actual foam prices, but I think I remember Gene liking this place. I buy mine off a delivery truck.
You would probably want at least HD-36.
I buy over the counter, but they also ship, standard sizes or cut-to-spec.
http://www.sunshinefoam.com
Don't know where you're located but I get all my foam from Foam-to-Size
out of Ashland, VA. (800) 548-5508.
Webpage
http://www.foamtosize.com/
You could give these guys a try:
http://www.foamforyou.com/
I've ordered from them and they were very helpful with questions we had and they're website has a lot of good info.
We don't order a lot of foam but one of the things I remember about ordering foam is that its expensive to ship.
Try to find a supplier near to you if you can to minimize UPS or USPS costs.
Jim