Is Differential Stretch in Upholstery Fabrics a Problem?

[Blucher]

Hey, all, new guy here, trying to teach myself upholstery (I worked in an upholstery shop during high school but that was 40+ yrs ago)...

Question: For upholstery fabrics, does differential stretch -- where the fabric will stretch more one way than another way -- should such fabrics be avoided for upholstery work?

I'm fixing an office chair that gets a lot of use -- it needs new foam, and fabric is ratty -- and I bought some heavy 100% polyester gabardine to cover it with. It's heavy and looks tough, but I guess it's a twill weave and has more stretch in one direction than in other directions. (In my case, it stretches on one bias a lot, whereas it has almost no stretch on the warp, weft or other bias.)

I'm curious whether, over time, this fabric will "relax" or "permanently stretch" in one direction more than in other directions, leading to looseness in that direction? Is this material going to give me trouble if I cover the seat of my office chair with it?

Another question: Should I orient the "stretchy" axis to be parallel to the length/height of the chair, so at least when it stretches out, it won't be cockeyed or angled?

My hunch is that fabrics that stretch equally in all directions would be better for upholstery but don't know -- maybe it doesn't matter?

Thanks in advance for any clues.

[MinUph]

Most fabrics will stretch more in one direction. If it isn't a ridiculous amount dont worry about it

[SteveA]

Welcome -- Most here are your age group - you're right at home.  This trade hasn't changed much in 40 years but a couple of things I can think of and maybe others can add -  tacks to staples - lighter hoses -
better glues, better foams - but labor the same.  I insist customers get upholstery grade fabric if they are supplying their own - I have a hard enough time with that :)
SA

[gene]

If the weft threads are stretchier than the warp threads that may be an indication that you have drapery fabric and not upholstery fabric. 30,000 rub test count is a good rule of thumb for upholstery weight fabric, although fabrics that will get little or no use can use less. A tight weave is also important. Hold the fabric up to a light and if you see a lot of pin holes then it is a loose fabric.

And like Paul said, you've got to have a lot of stretch for it to become a problem.

For your fabric, if you can, run the stretchy direction left and right on the chair, and run the less stretchy direction front to back. And always use poly batting (dacron) over the foam. Do not put fabric directly onto foam. This helps the fabric to slide back if pulled forward when people are getting up off (sliding off) the chair.

I started upholstery 16 years ago and by far the most difficult part of this work is the stretching of fabrics, especially when sewing. And it's not only that fabrics stretch, but also that they stretch so differently. You get used to one fabric and the next fabric is totally different. I think this makes upholstery sewing more difficult than wood or metal working.

I was not a Spring chicken when I started upholstery either. I've enjoyed it so far.

[kodydog]

I've been in the upholstery business for close to a lifetime. And in no way am I an expert in fabric. But I have worked with many and can honestly say I have never heard of polyester gabardine. So I looked it up. What I found is polyester gabardine is best suited for overcoats, trousers, suits, uniforms, and windbreakers.

Now that's not to say there is no such thing as an upholstery weight fabric called polyester gabardine. I've just never heard of one.

So that gets me to wonder, did you buy an apparel type fabric to cover your chair? The reason I ask is because apparel fabric works much different then upholstery weight fabric. And some (most) apparel fabrics are not suited for upholstery. This may explain the stretch. 

[Blucher]

Gosh, thank you all for the really thoughtful, detailed replies. I really appreciate your help.

The fabric I bought is from a place near here that sells "closeout" fabrics. I think he buys stuff from mills in NC and then resells it. I suspect much of it is seconds or end runs / remnants or whatnot. Very little of the material is labeled, but this stuff was on a bolt and labeled. I was encouraged by it being polyester since I know that holds up fairly well to sun/UV and rot.

My office chair is failing in other ways, as well -- in the piston/gas cylinder, etc. for example, is failing -- and this project is as much for me to learn as it is to rehab my chair, so if it doesn't last very long, I can always re-do it the right way (another learning experience) or just replace the chair.

I'm also a welder/metalworker/woodworker and I've been messing with sewing machines for close to 20 years (though I just finally found a decent walking foot machine -- an Adler 67-GK373 -- at an affordable price) so I can relate to your comments, Gene.

Again, thank you all very much for your help. I suspect I will be pestering you folks in the future with more newbie questions, but will try to keep it to a minimum.

B.

[baileyuph]

No!  Actually, if there is none - you will see why when doing a seamless pad seat.  Especially ones
that present inside and outside curves.  No stretch can drive the requirement to do those type
of cushions with seams to avoid the wrinkles.

This discussion has meaning with vinyls and coping with wrinkles also.

A customer brought me some one way stretch vinyl, you can guess the rest (on pad with no seaming)!

Doyle