Years ago I bought two hot water bottles and knit two cozies for them. Later on I gave one of them to my niece, and we lived for many years with just one. This winter I decided we do need two again, so I bought one and got to knitting. I chose something fom my stash (as always currently), and that's Traveller by Dragonfly Fibers in color Bad Moon Rising. It's actually a sock yarn, but I found it so soft and beautiful, I wanted to use it for this project. Also, it doesn't itch at all, which is great for cuddling the bottle in bed at night. It's merino, which I usually don't use, but the yarn was a gift so that's why I did this time. I really like how it turned out! It's rather thin, but keeps the warmth in ok and is very, very soft to the touch!