Substituting Yarns
Carol contacted me to ask: “Do you have any idea what ply Quaker Natural Fluffydown would be?”. Unfortunately my reply emails have bounced and since I suspect that we’ve all come across a vintage pattern and struggled to identify what thickness the original yarn was, Carol’s question has inspired this post.
My advice in such matters is nothing stunning I’m afraid. There is no magic, comprehensive list (that I know of) of yarns produced through the ages and their equivalent modern substitutes (though some partial lists exist). Don’t let this put you off attempting a pattern though, it just means you have to embark on some detective work and experimentation before you begin.
Generally vintage patterns are in finer gauge yarn. 4ply (fingering) seems to be the most common, particularly for patterns before 1950. Underwear, baby garments, and other delicates often use 3ply yarn (or finer). Double-knit (8ply) is generally only used in vintage patterns for rugged outdoor wear but after 1950 it is more commonly used for standard garments.
You can’t always take a pattern’s yarn specification at face value; it may call for “2ply” yarn but that probably doesn’t equate with the thickness of a modern “2ply”. So you do need to consult other aspects of the pattern to confirm what modern yarn will be suitable.
If a pattern gives you both the needle size to use and the stitches per inch for tension then finding a substitute yarn is pretty straight-forward - if you can reproduce the tension then you are on the right track. Look at the needle and tension specifications on a yarn’s label to see if it’s close to the requirements of your pattern and you’ll know if it’s a potential candidate for your project.
If the pattern only gives you needle size and a finished measurement of some description (e.g. Bust) then you can deduce the appropriate gauge by working out how many stitches form the garment at that point. For example if the pattern has a finished bust measurement of 36 inches and at that point in the pattern there are 127 stitches on the front and the same on the back that means that there are 254 stitches in total to form the 36 inch measurement. 254 divided by 36 gives a tension of 7 inches per stitch. This gives you the tension for the width, if a length measurement is specified for the garment then you can deduce the rows per inch as well. Be aware that many bust measurements are actually the size the garment is to fit rather than the finished size of the garment, but hopefully you can account for ease accurately enough.
Those patterns that say things like “a pair of bone needles” and provide minimal, unhelpful (e.g. “white merino wool”) or no yarn specification and no garment measurements are the real headache. Then it’s a fun puzzle of: guessing what sort of thickness yarn is appropriate for the pattern, determining what size needles can accompany that yarn and give an acceptable stitch tension for your liking, examining the pattern to get an idea of the number of stitches at key points in the garment, and then swatching with different combinations till you think you’ve found something suitable.
Determining the appropriate yarn for a project is a great excuse to litter the lounge with needles, yarn, and important notes on pieces of paper and not feel at all guilty about it. After all you’re doing important research that will enable the construction of a fabulous garment.