A solar pocket is made by taping a flexible black material all around the edges of a piece of glass, plexiglass, or other transparent material, forming a pocket. The back side of the black material is covered with insulation. A small part of the seal around the edges may be left loose for easy opening and closing. A solar pocket appears much like an AquaPak, the main difference being that for the AquaPak, the black absorber is rigid and the transparent front is flexible, while for a solar pocket it is the other way around.
A smaller solar pocket may be placed within a larger one, with spacers to create a 2 cm insulating air gap on all sides. A reasonably well-designed double (or triple or more) solar pocket, even without reflectors, can easily get hotter than boiling and melt and/or warp its own plastic components, even if the ambient temperature is at or below 50oF (10oC). For this reason, it could be usable to convert recycled plastic into sheets, panels or other structures.