Basically, the panel frames are constructed out of some clear pine I ripped. The wood was cut to 1" x 1.75". The large panel above is about 88" long and about 46" tall. Along with the top and bottom piece, I used 4 vertical pieces. I glued them and used some 16" nails to hold them together. They are very strong. The pine with the internal braces makes the frame very rigid so when pulling the fabric around, it it holds it shape well.
Thanks for the details. Was very helpful.
I worked on my panel frames last week/weekend. Used 5/4x4" finger jointed pine ripped in half to create roughly 1"x1.75" pieces as you did. Went with pocket holes and glue to join the corners. Still have to add braces to the larger panels.
Since my larger panels which are not quite as wide as your large panel, I'm thinking one horizontal brace and one vertical brace should do the trick.
Looking forward to seeing the last mile of your build.