If you count panels as a single block, I have made some 36x44. For a pieced block, I made a hunters star where each of the 9 blocks was 12" giving me a 36" block (it was a last minute request to do a raffle quilt). For the panels, I do creative borders -- and I did the same with the hunters star. What I have found is to put some smaller blocks or a piano key for the border. If you do QAYG, then you can build the border on the batting and backing -- that way the only heavy part would be the center.