Prosceniums

[CvdC]

Which to choose?
I went through all the photos and have produced this set of fundamental designs.

[Chris]

That should be useful to someone planning a proscenium Chris. But I notice that you have given them all a constant wing width - which is just the thing that changes, essentially with the method of frame construction - and this of course effects the whole proportion of the proscenium.
All you've really shown is how the shape of the top can change - but it is proportion which gives character.
For example, if you follow the way of manufacture shown in Edwin Hooper's "Hello Mr. Punch" then this allows the full width of the from for action, and the proscenium has a low, wide-screen appearance. If, however, using the same basic booth you reversed the side wings so that they encroached on the playboard width (allowing wings for draw curtains perhaps) you would have a much more square looking proscenium opening. The frame, however, would fold properly.
Again, with the same frame, use a bolt on proscenium and then you could have wider proscenium wings protruding both sides of the uprights giving a different appearance again - but you'd have an extra piece or pieces to carry.
The search for the ideal proscenium, like the swazzle, is probably never ending.