The curtain on our TT runs along a plastic track screwed to the ceiling, the curtain has sliders sewn into the upper edge.
The DW made a curtain for our last pop up. I bought an aluminum I beam style track, screwed it to the roof, and used little roller things on the curtain.
Both of these styles work well, if you have a fabric store nearby, and a sewing machine. I have an idea even the aluminum track could be formed into a gentle curve if necessary.
Every day's a learning experience, though sometimes not what we expected.
2012 Jay Flight 19RD
2016 Ford F150 XLT 2X4 SC 3.5L Eco Max Tow
2010 Tundra TRD DBL Cab (Traded)
2 new fluffy Corgis, Bayley and Stanley