OK. Thread Hijack!

How to write "DO NOT FOLD" on a large envelope?

Lazy translate: Не складывайте

Side note: I'm not impressed by the Russian Mail or FedEx, UPS, DHL package delivery in Russia.
Russian Mail is horribly slow. 2 weeks for a post card is, to be kind, bad.
One of my "kids" stated: "Russian Mail is still Soviet".
UK and Western Europe is a week for a post card. OK. Low priority. Czech Republic, Ukraine, Latvia, Bulgaria is a week. Belarus up to a month.