"Latten" rings are made from a copper alloy, and are decorative. In old archaeological texts, the word bronze was used liberally to describe ancient metals which were not gold, but that sort of colour, and which were used to make pieces of arms and armour. To the surprise of many, modern analysis showed that a lot of ancient "bronze" turned out to be brass, an alloy of copper and zinc, not bronze, which is copper and tin. Much Roman armour is brass. It takes some amount of analysis to determine what type of metal a thing is made from, and so to be on the safe side, when archaeologists today write reports on these things, they use the clumsy term "copper alloy". Since I have a degree in archaeology, and have been initiated into the inner brotherhood, and wear my desert boots, hand-knit sweaters, and beard with pride, I too ought to use this term. According to my Oxford dictionary, "latten" refers to an alloy of copper, zinc, lead and tin. I think that these are listed in their order of the amount of each which goes into the whole. The first two would make brass. My guess is that the lead and tin were added to make the metal more maleable and ductile, that is, more easily wrought, since brass is not easy to work (wrought is the old-fashioned irregular past participle of to work, still used by blacksmiths).
My byrnie has lines around the collar, arm holes, and lower edge in copper alloy rings. I used phosphor bronze split ring washers, bought through a hardware shop. These things are made for use in environments where corrosion is a particularly likely hazard. If you were to bolt some things together which were destined to be submerged in the sea, you might prefer these washers to steel ones. They were a bit more expensive than ordinary links, but if memory serves me well, I only needed about one thousand of them. They proved to be a lot weaker than the steel links, and I broke a few during linking.
I decided to stray from the Wallace Collection shirt's design, and instead of putting the latten rings around the very edge of the shirt, I put ordinary rings around the edge, and had a swathe of latten rings inset by a couple of rows. I thought it would look nicer. You decide. Some mail garments have very many latten rings worked into the pattern. I've seen some which form a heraldic device on the chest, others with a diamond pattern running throughout the whole garment. Most of the very fancy use of latten rings I have seen has been in suits of Near-Eastern origin, from Persia and the like. Anyway, my point is that one has a certain amount of licence with the use of these rings, but that to be utterly true to most European garments, the latten rings should be on the edges.
Shirt A2, our model, has three rows of latten rings around the arm holes, one row around the collar, and two around the bottom shirt edge (I would say "hem" but mail has no hems literally). Those that are round the arm holes, I noted (you will not find this in any publication), were against the grain. Given that a change of direction in the grain all the way around the ends of the arms involved a hiatus which is messy in comparison to continuous rows and columns of mail, this may seem odd, since the rings are there for decoration. I think, though, that I have the answer to why the makers of this shirt did this.
My shirt has latten rings which are linked with the grain, as seemed easier and logical. I have four latten rows at the ends of my sleeves, but to the casual glance, it looks as though I have three on one arm and four on the other. This is because the left and right sides of a chainmail shirt are not mirror-images of each other, as the grain on the torso continues straight across. For a shirt to be symmetrical, it would have to have a change of lie of the rings down the front - a sort of watershed. From one point of observation, one sees on my shirt the edges of rows 1 and 3 of the four rows latten, and the profiles of rows 2 and 4 on one sleeve; while one sees the profiles of rows 1 and 3, and the edges of rows 2 and 4 on the other sleeve. This gives the impression that one sleeve has more latten rows on it than the other. However, if the rows go against the grain, both sleeves will look more even. I realise that this paragraph may be a bit confusing, but I have good hope that you'll understand me.
I am suggesting that the makers of shirt A2 (perhaps having seen a shirt like mine) knew that unless they changed the grain of the latten rings on the sleeve ends, that the sleeves would look asymmetrical, and so they avoided this.
The makers have also altered the way they made the neck hole, for the benefit of the latten rings. On the sides of the neck hole, there are three rows of iron links against the grain. Thanks to the change of grain direction in the iron rings, the latten rings are able to make a smooth and even circuit of the neck. However, if the wearer's neck pressed sideways against these side of neck rows, it would be a fair bit less comfortable, since the neck would be against the edges of rings, which would be taut (as you know, mail gives in one direction in a different way from the other) and unyielding. The neck is ten inches across, however, so perhaps the neck never came close to the edge, so it wouldn't matter much.
MAIL ARMOUR MAKING
