A plain white cotton shirt comes with the Elephant Romper outfit (#7) and the Corduroy Suit (#5). All of those that came with the Elephant Rompers have decorative navy-blue zig-zag stitching around the hem of the sleeves and the neckline.
The white shirts that do not have decorative stitching are a clear minority and only came with the Corduroy Suit. The Corduroy Suit generally comes with the plain shirt but could have come with both.
So far, it appears that if the jacket in the Corduroy Suit is the tagged piece in the outfit, the shirt is pure white; if the shirt is the tagged piece, it has blue stitching. I have no data to back this up. In my personal experience so far, both of my plain white shirts have been with KT outfits. Comments are very welcome.
UPDATE: The white shirts started coming out on KT kids in the Cord suits very early. WE now have evidence of one on a triple HK KT kid.
The zig-zag decoration on the shirt can be used to identify the outfit’s factory of production.
This is useful because, in many cases, it is the romper or the jacket that is the outfit piece that is tagged, not the white shirt. If the white shirt is missing or becomes separated from the rest of the outfit, it is difficult to know which white shirt can replace it.
Some of the factories appear to have a distinctive look to the zig-zag pattern used on the white shirts. If you match the pattern to a factory, you can match a shirt to a shirtless outfit.
The pictures below are the factory patterns that I have confirmed. If you have a #5 or #7 outfit that you know came together and is from a factory not seen below, I would appreciate pictures.
For PMI factory information visit Unique Accents: PMI
If you have a shirt that does NOT match the patterns here, I would welcome the information. It may be that a factory produced two different stitch patterns, or it may be that the patterns used for the two outfits are not the same.
Factory information that I know I am missing: