This is a Sticker "Flowers" by Tegamiya (matsumi yoshimura), who designs stationery in Japan.
Stickers that can be cut and used wherever you like.
You can choose the size of the envelope and the place to put it.
Tegamiya is the artist who inspired me to start my own store, and I started this store because I wanted to sell her products.

Length is 297mm
Height is about 15mm
Pack of 9 sheets