Choosing the most durable slipcover fabric will depend on your household, since different homes have different needs. One of the things to consider is the rub-rating of the fabric, which indicates how many times the fabric can be rubbed by a test machine before showing signs of wear. If your furniture gets heavy use in a family room, a high rub rating is important. Most quality cotton fabrics have a rating in the 15,000 to 20,000 double-rub range, which is usually durable enough for family use. Washing the fabric also counts as a "rub" of the fabric, so if you'll be washing your fabric very frequently, you may want something with a higher rating. The rub rating is no guarantee against pets that scratch and dig the furniture - eventually, they'll cause damage even to a durable fabric.
Synthetic fibers often have a higher durability rating than cottons. Our Charisma Velvet scores highly at 60,000 rubs, and retains its shape and color well after many washings. The polyester fiber is stain-resistant too, and the low-pile resists marking. Use it to get that cozy feeling for furniture everyone is constantly lounging on.
Outdoor Canvas is another great performer at 60,000 rubs, and has a smooth finish that mimics a cotton canvas. Since the acrylic fibers are fade-resistant, it will keep its color for a long time, despite sun exposure and repeat washings. If you have pets or small children and expect a lot of spills, Outdoor Canvas is a great choice since the acrylic fibers repel liquids and wash up clean without much fading. If your biggest battle is against muddy footprints and pizza sauce, you'll probably be pleased with an Outdoor Canvas. Just remember, don't put it in the dryer at all - wash and put right back on the furniture damp to preserve its stain resistant properties.
If you don't want a synthetic fabric, a durable cotton is the next best choice. A Mattelasse' fabric will be sturdy because of its thick weave; while Mattelasse' is more expensive, it contains a dense weave of quality, long-strand cotton fibers. Originally created for bedcoverings, it's designed for frequent laundering and gets softer with use. Like any cotton, its color will fade over time, but this can add to its French-country and Shabby-chic charm.
Next in line for durability, in my opinion, would be a cotton Twill or Denim. The twill weave's diagonal structure allows fibers to be packed closer together during weaving, producing a more dense, durable fabric than a plain weave (such as a canvas.) However, it's important to have a quality cotton, with a high percentage of long fibers that give the fabric strength. A cheaper cotton will contain too many short fibers and can develop frayed spots and small holes when washed (just like a cheap T-shirt). A heavy 10 to 12 oz. Twill is a great slipcover choice. Remember that cotton will fade with repeated washing, so try to wash the entire slipcover at once to maintain an even color. If you have lots of messes, we recommend having an extra cushion cover or two made to put on the sofa in rotation - then you can wash just the cushion covers more frequently, and the rest of the slipcover every third or fourth washing as needed.
The best way to preserve the life of your slipcover is to carefully follow cleaning instructions. Heat and chemicals are the enemy of any fabric, so take it easy on the bleach. Even with a white slipcover, use non-chlorine stain remover such as Resolve on any stains. If you must bleach a cotton, try some non-chlorine Biz or quarter cup of chlorine bleach dissolved in the wash water before adding the slipcover. And remember, nothing lasts forever - but if you choose carefully and take care of your slipcover, it will last for many years.