Dear Sock Pal,
thanks for stopping by and leaving a comment.
You can use each type of yarn that is comfortable for you. And it is no problem for when the yarn is not washable in the washing maschine.
I prefer to shop in little shops in my area and they are selling Regia and since a few week they also sell the rainforest collection of Opal. I also bought two skeins of yarn at handgefaerbt. The first socks I have been knitting were plain knit without any pattern because I used Regia yarn that pattered itself. After that I started to k5 p1 so that the leg is a bit more flexible.
I'm also knitting for a charity project (Arche) and I started some easy patterns. I never knit lace but I'm not the type to wear lace socks. Most of the time I'm wearing jeans and t-shirts, because that is the most comfortable cloths when you are having two kids.
I opened another email account and contacted my sockpal. We chat a bit and it was pretty hard not to tell anything about me.
The material of the yarn is pretty easy because she is allergic to most types of yarn. Her colour choice was very narrow so that is also not a big thing. Within the next days I will start to knit a pair of Jaywalker socks for me and see how the pattern looks when knitted with a yarn that makes stripes in various sizes. After that I will decide whether this pattern is okay for my pal or whether I better use another pattern.