seeking pearls on shadecloth design for gh

[jmforan]

I confess I'm a cart-before-the-horse breed and true to my nature, installed a gh with the misplaced faith that my enormous oak would provide adequate shade. Not!!! So Half of my plants are going under my bench to protect them from the avg. 4-5000 foot candles that So. California provides 6 hr/day in Dec. I need 1/4 of the bench area shaded to grow Phals, Miltonia hybrids and eventually Paphs. Can someone with handy skills suggest an indoor frame design for applying shadecloth? Your shade -making wisdom is my enlightenment!