Have you Copic lovers seen this tool?!?!? MIND BLOWN!
I have always used the standard copic chart. But I don't find it too useful in creating new colour combinations. This amazing chart groups by colour instead of numerical value. It'll make it so much easier to create combos now!
You can purchase the chart here for $5.99 US. It comes as a download with one file blank to colour, and the other pre-coloured. There's a second page just for the greys. I've added my own watermark just to protect the original owner, Sandy Allnock's copyrights.
Hope you find this useful too!