Following up from yesterday’s entry, I made several markers (see What is a marker? if you have no idea what they are) to compare efficiency for double and single folded lays. For both lays I used the same fabric width of 58″. The single ply area was of course, 58″, while the double ply layout was based on a 29″ width.
The double folded lay came out like so:
The single ply layout looks like this (clicking on either image will get you a larger image file):
As you can see, my claim that efficiency would be improved by 15% was unfounded -at best considering the scant 3% improvement (in larger companies, one could get a bonus for a 3% improvement!). However -and that’s a big however- in the single ply lay, there is a block of unused fabric that measures approximately 15″x15″ that would normally be taken up by the next repeat (size) in a production lay which would actually increase the efficiency. I’d have to make another marker with however many sizes to know with any certainty but I would guess -caveat considering how that’s been working out- that perhaps as many as five repeats could be lain in the space of four or at least six in the space of five which could increase efficiency by about 15%. By the same token, similar savings could not be possible for the folded lay. Long story short, doing the single ply still represents significant savings as a production yield pre-test and well worth the investment of time to do it.
Switching gears, I meant to explain two other reasons why sample cutting can cost more than one would hope. The first is that we cut more pieces than one would at home (nice RTW has lots of guts) and also, it depends on the provider’s infrastructure…
It was at this point that this entry became quite lengthy and since it diverges from yesterday’s follow up, I decided to post it as part three for tomorrow. There will probably be two posts tomorrow because I had to write a separate post as an aside to part three. The former will be about fusing maps. I’ll bet you’re shivering all over with anticipation to read that one. Be still your beating heart, tomorrow will come soon enough.
But anyway, feel free to post comments or questions on this follow up. Thanks!
This is exactly why, as a home sewer, I cut on a single ply lay. (Well, I also think it’s more accurate, because it reduces slippage, but that’s likely negated by my general lack of skill at cutting.) Given that fabric estimates on the back of home sewing pattern envelopes are overestimates to begin with, I end up saving about half a yard from the given amount of fabric required. As with most home sewers, as I don’t factor my time into my final cost calculation, so fabric is the most expensive part of the project. That half a yard can make a big difference.
Oooooo, fusing maps. Is it wrong that I’m actually excited about that?
You are sick. Sick I tell you!
I could go for a good fusing map too. Not that I need one but I still want it.
I’m with Sarra on the fabric saving. Single ply is the way to go, especially if you are matching prints across the fronts of garments. When making Boy Scout themed shirts for the offspring, the spouse, and the Scoutmaster I was able to save enough to eke out a shirt for myself.
And fusing map? I’m intrigued as well. Looking forward to tomorrow’s post.
Maybe I can save a bit fabric cutting single lay. But you can not compare those two cuts – single versus double lay. I would never cut per example the center back piece or upper sleeve in two different directions.
lg
heidi
Unrelated but very related:
Shrinkage tests.
Home sewing starts with pretreating the fabric. Industrial layouts spread the plies raw, but with shrinkage allowances factored in. CAD programs do this automatically when you plug in the figures.
If you’re still at the manual level, you’ve got to know how much your fabric will shrink each way, or your jeans (to take the most awful standard example) will be too short after a few launderings.
So, gang in a post on this?
Anecdotal experience:
Efficient layouts kick in around the third repeat, certainly by the fifth, of a single size, and much faster when you’re doing clusters of sizes (i.e. 1 XS, 2 S, 3 M, 2 L, 1 XL).
I’ll bet the single ply layout of 1 S, 2 (3?) M, 1 L would be significantly better than the same on folded goods.
Fusing maps? maps? Either I know this by another name or yet there is one more trick for an old dog to learn. I can’t wait!
Given that industrial CAD has allowances for shrinkage, and that fabric requirements on consumer patterns often have excess, is that excess to allow for fabric shrink tests? Or do consumer patterns also have allowances for shrinkage built in? I’ve found that they are universally roomy when made right out of the package, exclusive of the issues with fit they will typically have.
FUSING MAP?! WHY MUST YOU TEASE US SO? *ahem* Excuse me.
Looking forward to tomorrows posts.
Count me in the shivering and sick group… Can’t help it, these things just are so darned interesting!
Single ply is also much more efficient when dealing with asymmetrical pieces.
What the heck is a fusing map? Can’t wait to find out as I think it is going to be important. ; )