Actually I believe the Velcro fabric has changed from when I first bought it 27 years ago. The stuff that failed has a thin foam backing, and even though it was very securely glued with rolled out white glue, one day the foam just disintegrated and the fabric fell off the plywood panels, corner samples attached. It was quite a sight to behold! Very Dali-esque.
The stuff I have now was also glued firmly into place about 10-15 years ago and my plan, if the loopy pile ever starts flattening too much, is to move all the samples over to one side or the other about an inch! I don't think this stuff has any foam on the back of it, just a nice thick fabric and by this time I do believe I had used fabric adhesive. It is firmly attached!
Watch, I'll go into the shop tomorrow and everything will be dripping down the walls. Sorry for the Frankenthread.
Carry on.