Doubleweave vs Summer and Winter
Hi there, Lydia!
The only real similarity between doubleweave and summer and winter is that they are both unit weaves (composed of threading and treadling units that can be used with block, i.e., profile, drafts). You can therefore weave the same block designs in doubleweave as in summer and winter and vice versa.
They are completely different, however, in structure. Doubleweave is composed of two sets of warp and weft (two weaves) in which pattern vs background is created by which weave (color) is on the face and which on the back in each block. Summer and winter is a supplementary-weft structure with a plain-weave ground cloth and a pattern weft, in which the difference between pattern and background depends on which side of the cloth the pattern weft shows in each block.
In museums, doubleweave has sometimes been called "summer and winter" because, I think, in early American coverlets, there is usually a dark side and a light side, sometimes referred to as the summer side and the winter side, but this terminology really never had anything to do with structure. It might be from the summer side/winter side quality that summer and winter got its name originally.