Distinguishing high vs. low armholes on eBay?

[vtgdance]

Since I'm too diminutive (36S 29W, vanity XS) to find many items in my local thrift stores, I've been working on my eBay vintaging skills to compensate. So far, my batting average for usable clothes is about 1/3, never paying more than $30-50 for an item unless I've methodically measured something similar.

Low armhole jackets (and shirts) have been the bane of my existence, since I wear these while swing dancing. How should I ask an eBay seller about the armholes on the jacket?

I plan to send pictures that indicates where to put the measurement tape, e.g.

1. marking up the place to measure on a jacket pattern

2. asking for #49 on this diagram:
http://www.pendragoncostumes.com/images/lineman.jpg

#2 is a backup in case the seller doesn't understand #1.

I'm not sure how I can do much better than using #1 w/ shoulder and chest measurements for direct comparisons with my jackets and shirts. Based on my data, 9" looks like the maximum I should accept.

10" H&M (38R): Can't crossing arms. Raising arms (45 degrees) looks terrible.
9" 1950s vintage jacket (37R): Can cross arms. Raising arms (45 degrees) looks better, but still not great.

Given that my arm measures 16" around at the shoulder, can I do better with even smaller armholes? Most of my shirts have armholes around 9"-10"; would I run into problems if I paired these with 8" armhole jackets?

 

[Bird's One View]

You could ask for both overarm (shoulder to sleeve end) and underarm (along the seam) measurements. The greater the difference, the larger the armhole. These measurements are probably easier to take than measuring the armhole directly.

The only problem with having a larger shirt armhole is that the coat will pull up the shirt sleeve and the shirt cuff may disappear.

Aren't there coats made specifically for dancing that have the arms cut to point straight out, so that they don't even hang cleanly? I have a photo of a dancer with the smallest coat armholes I have ever seen.

 

[Sator]

If you want an arm scye depth get the seller to measure it like this:

The line from c to d runs along the bottom of both arm holes with the coat lying flat. The arm scye depth runs from a to b. Point a is the top of the centre seam (excluding the collar).

Your own ideal arm scye depth is measured like this.

Step 1:

Have the tape measure run from bottom of arm pit to arm pit. Mark the point that the tape measure intersects the centre seam with chalk:

Measure down from the top of the centre seam to the chalk mark:

 

[vtgdance]

Aren't there coats made specifically for dancing that have the arms cut to point straight out, so that they don't even hang cleanly? I have a photo of a dancer with the smallest coat armholes I have ever seen.

I haven't seen these before. I'd love to see this picture; could you post or PM it?

Based on a quick Google search, I think you're referring to jackets cut for ballroom competition, which are cut specially for a particular type of hold:
http://www.eijkhout.net/rad/data/ballroom_costume.html

Since I dance vintage swing (e.g. Lindy Hop, Balboa, Charleston), which has different body positions, holds, and visual aesthetic from ballroom styles, I don't think getting a ballroom jacket would be the ideal solution.

Fedora Lounge has a few sewing swing dancers; I'll try asking them for ideas too.

The line from c to d runs along the bottom of both arm holes with the coat lying flat. The arm scye depth runs from a to b. Point a is the top of the centre seam (excluding the collar).

Thanks for describing how to take these measurements. I tried these on my jackets, but still can't make sense out of how to predict why they behave differently. a-b measures the same on all the jackets (10"). The chest width is different on all of them; would this cause sleeve length problems with crossed arms?