I think I figured it out. Just need to buy global forever stamps for the SASE.

I have a further question, if you download some photos, can you just print them out on a home printer? Will normal printing paper be fine to get autographed?

What is the best size of photo to send in a letter to be autographed? I read that collectors prefer 8 x 10 inches (20 x 25 cm) but that seems way too large to send in a letter? Can it be any size?

Do I have to send my own photo for them to sign or will they supply one of their own? I’m trying to write to Sadie Sink and don’t want to lower my chances by not sending my own but would prefer to have them choose one.

How can I get an autograph from someone in the USA while I am in the UK?

Anybody know Sadie Sink’s mailing address to send fan mail with an autograph request? Don’t want to get wrong.