I use a self inflatable 3/4 length pad (thermarest or other brands), fully deflated and folded in 4 as packframe, in totally frameless DIY packs (into a special "inner "slieve"). Enough support, and comfortable up to 10/11 kg, only drawback is the pack tends to "stick" closely to my back, not very pleasant in hot weather. The back part of the pack has 2 extra vertical pieces of padding which help a bit for "aeration".