Do not do it.

My 48 page passport is full. We only get ours for 5 years, so its not a big deal as its done next year, but unlike Americans, cannot add pages.

Last year, I had a Kenyan visa that fell off on its own, great I thought, extra page.

An immigration officer in MUC could see that there was glue residue using his UV light thingy and demanded to know what happened. Luckily I still had the visa with me.