Pinned swatches

I want to fasten them in pages of three but worried I may ruin them if I put something through them to keep them together. I could tie them with some kind of string-ribbon or pin them with a split pin I'm just not sure if the gold pin would look odd.

I ended up pinning them with a split pin, they do look a bit large for the size of th swatches and would have liked to use something smaller but this was most accessible in the time I had and keeps them together without causing any mess apart from on the back where you can see that the pin is split.