Guest book??

We went to a wedding that had one of these last fall and we had to sign our names in our thumbprints it was veyr pretty because the bride and groom choose 5 complimently colours and the tree ended up looking so fasntastic with all the colours together !!

The initial idea sounds great! I like it too!

Yes I was think it would be nice knowing who is who. I like the sign idea. Already have one if we go with signing the canvas.

I like the initial idea thank you

The canvas is 2feet by 3feet. We are getting married February 18, 2018. We want to do multiple colors. Thank you

I agree, it's up to you! I would want to know who was who because the guestbook is how you remember everyone who was there on your day. My friend did one for her wedding but they didn't tell us to write our names so when she got it back, she had no idea whose was whose. (Her SIL was supposed to tell people but forgot.) If you want names, make sure to put a little sign with an explanation! (And hand wipes to clean the ink off their fingers)

My cousin did a thumbprint tree and we put our initials in the thumbprint

I haven't seen either done before, but I do like your FSIL's idea! How big is your tree? Do you think your guests are the type that would want to write you and your FH a note?
It also depends on if you'd like to know which thumb print belong to who. Perhaps you could ask your guests to initial their thumb print as an alternative to having a guest book.
When are you getting married? And are you planning on having one colour ink, or multiple? If multiple, could be cute, especially for fall wedding! Or just green for like a spring/summer!
So many options love the idea of a thumb print tree, very cute