I'm often reluctant to post glaring mistakes (unless they're funny), but this one is a really good illustration of why folks with large busts can't just buy standard sizes and "get them altered" to fit.

This waistcoat was drafted to my measurements using standard drafting methods, but despite multiple rounds of adjustments, it still doesn't fit in the bust.


Pattern drafting geekery 


Standard drafting methods don't account for bust:waist ratios of more than a few inches. They pull in extra fullness at the darts and side seam, which works for small adjustments, but there are limits to what darts can do before things start getting cone-shaped.

Pattern drafting geekery 

3/ what I need to do instead: draft the block to my upper bust instead of my full bust measurement, and then do a full bust adjustment.

Because I drafted the pattern to my measurements, I already have the extra room under the armscye that a full bust adjustment would add - but I need the extra room in the front, not the armpit. A full bust adjustment will move it where it's supposed to be without making the darts ridiculously wide.

Pattern drafting geekery 

4/ and you can see what this means for buying clothing off the rack*: alterations work great for small adjustments (though they're still a tax on people with non-standard bodies), but for differences of more than a couple inches, there are no quick fixes. The garment has to be remade - and that's easier to do from scratch than from an existing garment.

*That's the industry term, not a pun, but lol

Pattern drafting geekery 

@Annalee Love the description and reasoning.

Difficulties like that were a frequent source of arguments between my boss and I. We were working on a pattern drafting software and they wanted to dart all adjustments because it was easier to code.

I mean I usually take the hardest route, but i thought the results were better. Never got it where I was happy, though, before I left.

Thank you.

Pattern drafting geekery 

@dmoonfire oh neat, which software? I've been using Seamly2D recently, but while it's got good tools for rotation, an FBA will need to go in by hand I think.

I should take the time to work out a basic block draft that accounts for it from the start (which I guess I'd do in the same way as a manual adjustment but just change the order: draft based on upper bust and then use a formula to apply the appropriate FBA to the grid before drawing in the pattern?)

Pattern drafting geekery 

@Annalee It was called The Complete Clothier (TCC) but I haven't been involved since 2008. The main idea was that you could measure everything (pretty much from every joint to joint, and width), adjust for how tight you want it, and then we would use that to draft out a pattern using 2D vector which could then be printed out as the pattern.

Like inseam could be entered directly, extrapolated from your height, or calculated from the various lengths of your leg and foot.

Pattern drafting geekery 

@Annalee The 2D pattern was basically just turtle graphics in the back end with a lot of math, so we used cos, sin, etc along with the measurements to build up the pattern along with a library to let us figure out darting, etc.

Lots and lots of sewing. :D And fitting. There were a couple days when we had fifteen or twenty ladies using the patterns and submitting bugs where it didn't fit, etc.

Pattern drafting geekery 

@dmoonfire that's cool! I haven't dug in under the hood on Seamly much but it's basically a vector graphics program with pattern drafting tools added. I'm still learning my way around its quirks so I used a tutorial for the block; now that I see how it's doing blocks I can do my own with the FBA baked in where necessary

Pattern drafting geekery 

@dmoonfire (it won't do if statements, but if I set it to use upper bust and add front fullness based on the difference between upper and full bust, it *should* resize gracefully?)

Pattern drafting geekery 

@Annalee Ultimately, all drafting programs are going to be vector graphics in some manner. It's pretty cool how one translates a 3D shape to 2D patterns but it is also complex.

I also had the beginning of taking the 2D pattern and putting it on a 3D human model and simulated draping.

There are days I wish I still had TCC to play with, mainly because it did some fun things and I think it could have gotten further. :(

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