I had a pair of long curtains where the whole leading edge of the lining had rotted and the edge of the curtain had seen much better days. Luckily they were full enough to be able to cut off the whole bad piece. They were patterned fabric and I bought a length of plain fabric in one of the colors and encased the whole edge with a strip - like fat binding. They lasted several more years and were still hanging in the house when I moved out 2 years ago.