SD tailoring (suit making)

I've done something similar to this with pattern diagrams from Otome no Sewing. I did this purely out of curiosity, because I had the same question as you a while back. The resulting garments were good

(I'm not a professional seamstress and I'm sure they'd have some criticisms about this method! The basic idea should work though)

The pattern diagrams were provided in S - M - L commercial sizes, defined in the book with measurements for bust/waist/hip. I chose the measurements for M, then found the ratio of the human scale to doll scale.

M bust ÷ Doll bust = Ratio 1
M waist ÷ Doll waist = Ratio 2
M hip ÷ Doll hip = Ratio 3

Find the average to get your doll's true scale:

(Ratio 1 + Ratio 2 + Ratio 3) ÷ 3 = Scale

When drafting the pattern from the diagram, divide every measurement in the diagram by the scale determined previously.

I used this method to draft a 1/4 MSD blouse and dress. For the blouse, I simplified the darts to reduce bulk + improve appearance and it fit really nicely.

The dress came out a bit weird; it fit alright, but the waist was cut lower than my doll's natural waist.

If things fit oddly it is likely because the pattern is designed for human proportions rather than doll proportions - like long legs and very small waist, compared to the "chubby" waist and average legs most people have. Doll arm length usually uses realistic proportions so sleeves are less likely to be the wrong length. For male dolls, long legs, very broad shoulders/chest and thick biceps are the most likely issues I can think of when adapting human patterns.

If the drafting instructions use your raw measurements as a starting point to calculate the size of the pattern, then it should be possible to use the doll's raw measurements to make a doll size pattern using the same calculations/instructions as the human pattern.

As far as accommodating joints - no need to worry, every single human pattern already includes ease and is designed to accommodate movement and so it can accomodate a BJD's movements too

 

Not so much for the oatter but yes when choosing fabrics and, where you can, cut out as many layers as possible -

For example, a cotton drill that works on a human for torusers, might be too thick/heavy.bulky for a dolls cale (like making human trousers out of heavy canvas).

I had a friend who was a professional costumer, and in her downtime liked making clothes and costumes for dolls, but they didn't always work because she used offctus from her full sized projects to make the doll clothes and they were frequently too thick and lacked the drape to work well in doll scale - one otherwise lovely 18th Centuury style gown for a 1/4 doll resulted in the doll not being able to put her arms down at her sides because of the bulk of fabric in the sleeve and bodice between her arm and body. Also, she never got the hang of "cheating" when it came to the layers of an outtfit. Even using the thinnest of fabrics, if you include all the layers of a human outfit the end result may look unnaturaly bulky on a doll.

A Tudor ensemble wich would consist of a chemise, kirtle (undergown), and gown for a human can benfit hugely in doll scale by faking the chemise and having just the neckline and sleeve bits that would show sewn as part of the kirtle, OR keep the chemise as a separate garment, and fake the kirtle by having only the parts that would show sewn as part of the gown.

Leaving out linings and only interlining with ultrafne interlinings where absolutely necessary can also help

Teddy

 

A lot of helpful points above but I'd add a few thoughts about accommodating clothes for bjds because it's a bit annoying to realise some things through trial and error

Resin is not soft like the human body so very tight-fitting clothes might need some compensation to be possible to put on dolls - switching to stretchy fabric (or cutting on bias), adding slits or extra openings for access etc. Some clothes end up needing the removal of the head or hands to be put on properly and sometimes it's nicer to just have access features not to have to do that every time. Some clothes do restrict joint movement as the ease on a human pattern is not always enough (again, we are soft and dolls are not) but there isn't always a ton that could be done about it in patterning stage other than making the clothes less tight.

Bulk is another big annoying bit in doll sewing - it's more or less of a problem depending on the size of the doll but with smaller sizes (1/4 and below especially) it can really make something that looks right fit weird, so it's sometimes necessary to leave out the lining, cut garments out in a way that requires less seams or use thinner fabrics altogether. The latter is really helpful and I wish I had taken that advice earlier myself

Good luck sewing, hope to see what you make also

 

You can use human sized patterns for dolls, but if they have any measurements specifying how far out to drop or raise a line, or how long a specific line should be or something similar, you'll want to divide that by the scale that your doll is. So if your doll is 1/3 scale, divide those by 3, by 4 for 1/4 scale, etc. Which I've found means working in centimeters is much much easier than in inches when drafting for dolls specifically. It doesn't generally make a huge difference when drafting at full scale for me, but the fractions you get in inches can be ridiculous.

You do definitely need to adjust the way you construct things for dolls-- hemming things before closing up the seams (because otherwise the space is too small either for a machine or to easily get a needle in to hem by hand), sewing in inset sleeves before sewing side seams, eliminating layers and bulk in places, forging some things like interfacing in some places (since you mention tailoring for suits, leaving out the horsehair in the pad stitching for collars for example). Some of it is trial and error to see what you can get away with for how you sew and how you plan to play with your dolls honestly. If you don't plan on putting them in a bunch of complicated poses, clothing that's more snug in the joints might not be a problem.

Of course, with any drafting a sewing, mock-ups are key! Any little issue that might be ok on a human scale garment is going to be much more obvious at doll scale!