I decided that printing two different sizes of drying racks was not sufficiently sophisticated, so I designed and printed an adjustable plastic bag drying rack.  There is a central hub, with T slots in it; the four adjustable “wings” fit into the T slots (although they are actually L shaped, not T shaped, because it was easier to print that way). Each of the four wings consists of two pieces which slide past each other guided by three slugs on one that fit in slots on the other.

The two pictures with the bags on the rack are in fact different: notice that the wings are extended in one of the pictures to accommodate the larger bag.

My girlfriend commented that it was ironic to use so much plastic to make the drying racks in order to save plastic. I suppose that she is right!