Custom binding is a process that gives you the freedom to combine carpet in the right size and with the right shape, with a bound edge that may or may not have fringe. The carpet can be from designer remnants to rolls of broadloom that are in-house of special ordered.
Retail area rugs come in standard sizes, within a few inches of 5x7, 8x10, and 9x12. If you want a square area rug that is 10x10, if there is one available, the rugs that venture outside of the “normal” sizes can be pricey. To fabricate the same rug would cost the amount of the yardage needed, and a modest fee for the binding; it’s that simple.