Edited by BoingBoing at 2021-2-19 13:39
For those of you who would like to a substutue for a yarn that is no longer made, or is hard to get in your area/country, or you just don't like the feel of the yarn that your pattern recommends, here are some helpful things you can do to help figure out what would be a good substitue in no particular order...
Check out the book, Yarn Substitutions Made Easy by Carol J. Sulcoski which is here on PinDIY. It goes into great depth on how to substitute yarn.
If you have a pattern, which states the brand, weight, gauge, and needle size, you can use the site YarnSub dot com. All you need to do is enter the yarn name that you are supposed to use, and it will suggest substitutes from best to worst match. I've used this site with great success especially trying to knit up a pattern from another country where the wool is not available where I am located.
A third option is if the pattern is on Ravelry. Once you look up the pattern, you are given the details of the pattern, and several options to look at yarn ideas, projects, comments and forum posts. If you look under yarn ideas for the pattern, all the yarn that has been documented in projects used in this pattern will be displayed, starting from the most number of times used to the least number of times used. I've found thisto be one of my go to resources to trying to figure out what to use in a pattern.
Another option, which you may find more frustrating, is to take the yarn weight, gauge, and needle size from the pattern, and try to find something that is similar in your stash and swatch. No matter what if you are substituting a yarn for the original in the pattern, you should swatch to ensure you are getting the correct gauge for the pattern. Without the correct gauge, you can not be sure the sweater/pattern so it is important if you are doing a substitution.
Don't discount your local yarn store(LYS) and the knowledge that they have built up over the years. My LYS has extremely knowledgable people working there are they are willing to give me a hand if I run into a substitution problem and will invariably recommend something that will produce a fantastic piece.
These are just some of the options you have when you need to make a substitute for the yarn recommended in your pattern.
Feel free to add more substitution options and I hope it helps those that have to make substitutions for whatever reason.