Knitted Hot Water Bottle cover!

Cast on 38 stitches and move to DPN. knit first row to pattern. In the second row, for the vertical colour line include a stitch increase to bring the total to 40.
Continue to knit to pattern ensuring you have enough slack inside the project when colours are not in use so that later your HWB will still fit inside. Because of the colourwork I won’t have to line the inside of the project - the double layer of yarn should do the trick. Where there was no white/grey changing i kept the colour wrapped every few stitches to keep it orderly and to create the lining.
When doing the neck of the bottle for the white vertical stitches knit both and then slip the first one over the second. Knit the rest of that row the same.
For the next two K2tog for each except the white stitches remaining. Change to rib stitch and add a stitch every 10 until you reach the top of your HWB. Knit one row in Grey then purl the next before binding off.
And that's it!