The subtle colours of this spiral make it quite difficult to notice that there are four different shades. You could use bright colours to make it more spectacular.

You will need less than 25 metres/yards in each of the four colours.

The ebook contains patterns for eleven knit and crochet toilet roll covers based on mathematical concepts. It also has a section that will help you to design your own covers.

The patterns are not available individually but if you want just one I can supply it in return for a small donation to my favourite charity.