Many years ago, a company called Marit Enterprises in Kanata, Ontario made a device they called "Signe's Width Holder". It was a weft stretcher and it perfomed a function similar to that of a temple. Similar, but weft stretchers pull fabric while temples push. I had occasion to see one of these gizmos on a loom recently and was intrigued. I took photos and made a copy of the assembly instructions which the loom owner miraculously still had in the original box. Researching the device, I found only two references on-line. The first was a 1990s WeaveTech message recommending it and the second was a two year old Weavo post by somebody searching unsuccessfully for one. I like weft stretchers and use them often on pieces of moderate width where a temple would be heavy and cumbersome.
So, based on the photos and assembly instructions, I whipped up my own home-built version with a bit of electrical conduit, two single sided brackets, a dowel, a weight, paper clamp and some string. Here's a photo:
I'm posting this in case anybody else wants to give it a try. A buldog clamp (office supplies) grabs the edge of the fabric and is tied to a string. A weight (tackle from a fishing store) is tied on the end of the string and pulls it downward. The conduit is screwed to the side of the loom with the clamps and holds a dowel. Draping the string over the dowel converts the downward pull of the weight to an outward pull on the weft. That outward pull helps keep the selvedges straight. I installed one of these on each side of a loom for testing. Initial reports are that it works fine. At first, the dowel snagged occasional picks. I sanded the end of the dowel round to make the picks fall off, but then learned that we could simply slide the dowel back until the end sits just behind the fell line. Then it's less likely to catch a pick and the problem pretty much went away. All-in-all this "Signe's Width Holder" knock-off seems quite functional and easy to make. You could, of course, just tie a string from back beam to breast beam to serve the same function, but the dowels are stronger and more consistent than cords, which inevitably sag with usage. The dowel is also easily removed, leaving nothing but the sleeve behind. Here's another view with the dowel closer to the fell line: