I think the quality of the fabric is more important than the medium versus heavy (which I suppose is in the weight of the fabric). I used a "heavy" weight fabric once not even questioning the upholster's fabrics and within a year, it needed redoing, whereas the original which seemed more medium in weight had lasted 10 years to that point. I asked a person (who I came to know later) about the difference, and she told me (that's what she did for a living) that the contents of the fabric are very important. I cannot remember now what was in the fabric that did not wear well but the original was a heavy duty woven cotton jacobean and the second was a tapestry which contained a synthetic that did not wear well. Not that all synthetics are of poor quality, and I wish I could recall what she told me now but that was long ago, but I have also experienced the same in a very expensive sofa I bought in the 1980s and it wore very quickly and had what appeared to be a great heavy weight paisley but it was not. So I think the "quality" of the fabric is more important than weight.

In the interest of keeping this thread alive, and in response (much belated) to orcagirl, I say this: do you have both fabrics to feel and look at in front of you? Which was more appealing? My own understanding (not yet the voice of experience) is that acrylics and acrylic blends tend to hold up well to regular use, do not stain easily/ ever, and are, as you noted, less expensive than many other fibers. In this sense, if you like the "hand" of the cotton/ acrylic blend option, you are unlikely to be any less satisfied by it five years from now than today. However, if you do NOT have both fabrics in front of you to touch, answering becomes much more difficult! (Also, as an aside to justerrilynn, I LOVE the way those little stools turned out! Wow!)

Yes, my drapes are up year round plus have no sheers or other between them and the window pane. Surprisingly, the sun fade is worse or at least more noticeable on the sides facing inward to the room, along the edges of the drapes and where they puddle on the floor. Not really relevant to OP question, but I also have a problem with hooks and rings not being able to withstand the weight of the drapes, so am constantly rearranging hooks and mending tears at the tops. But these are older, vintage velvet and pretty sure are heavier than modern velvet drapery. They need cleaned desperately, but can you imagine the dry cleaning bill even if they would accept the challenge?

The durability of a fabric is usually expressed by the number of "double rubs," described below:" "What Does Double Rub Count Mean? While it might sound like a funny term, it is an important measurement of the durability of the fabric and could be the deciding factor in which piece of furniture you purchase. In the United States, fabrics are tested using the Wyzenbeek Method. During this process, a piece of cotton duck, which is a piece of heavy canvas, is repeatedly rubbed over the test fabric using a mechanized arm. Every back and forth motion of the arm counts as one “double rub.” This rubbing motion is meant to replicate the abrasive effects of normal use and the friction that occurs when you sit and stand. The test continues until there are signs of significant wear, which is defined as two yarn breaks. According to the guidelines, approximately 3,000 double rubs is equal to one year of use. Fabrics that can withstand more double rubs will offer more durability and longer-lasting performance. Double Rub Scale for Residential Use Heavy Duty: 15,000+ double rubs. These materials are ideal for busy homes that have pets and children. Medium Duty: 9,000-15,000 double rubs. This fabric grade is still considered fairly durable and may offer a more cost effective option for families on a budget. It is still strong enough to be recommended for use in family rooms. Light Duty: 3,000-9,000. According to wearabilty standards, this fabric will only last 1-3 years before showing noticeable signs of wear. For this reason, light duty upholstery is best for formal living rooms that aren’t used on a daily basis. Delicate Duty: Less than 3,000 double rubs. Because this grade of fabric easily wears, it is typically used for decorative details such as pillows and curtains." Most good fabric houses list this number on their samples. I'd contact Century directly.