Magazine Paper Weight

How many stamps do you think might want to send six pieces of paper and pasted on kraft paper?
The magazine collage is pictures thin, so I do not think it adds too much weight. But I could take pictures of all truly random things in the envelope, I'm sending it, so I really not want to go to the post or something, so any advice?
I would say that three of First Instance in Class ($ 0.42) stamps. I put four to be safe.
Shooting a Glock 19 9mm 31 round magazine