The closet in the baby's room has built in shelves that aren't quite triangular or square. They are 16 x 16 x 14 x 6 inches--a very awkward trapezoidal shape. Using upholstery fabric given to me by Laura of Butter along with some scraps I already had, I made custom fabric bins. The bins are different heights depending on the shelf. Each is lined and has a cardboard reinforced bottom.
I thought the fabrics were all very pretty and extremely sturdy. All of the bottoms, interior and exterior are a chocolate brown velvet. While the walls aren't reinforced, once the bins are in place and being used they should stand up just fine. I'm very pleased with how these came out. Now, I won't have any wasted space because of the odd size and despite my being a very poor seamstress and mathematician these actually came out looking good!