This spring I decided to do a test project with some foundationless frames from Kelley. I one hive, I started in the brood box with 2 foundationless frames between drawn comb. Had some very good results so I went to a couple of the supers and did the same thing. Foundationless sandwiched between 2 frames with foundation.
Well, when I pulled the supers all the foundationless frames were empty, but the foundation frame on one side had the comb built out into the space of the empty frame. Clear through to the foundation on the other side. Result was a 2-1/2 inch thick comb. I had to pull both frames at the same time but the FL had no attachment points at all.
Brood comb was built out in all of the FL frames in the lower 3 boxes, none of the honey comb was built out in the FL frames. Pretty stange?