Sticker Scaling with standalone and when layered

Hello, I'm looking to make my first sticker pack and have noticed that when you place a sticker by its self it is one size and then when you go to layer a sticker on top it is another size(smaller). Doesn anyone know the percentage or what the scaling amoutn is based on?


My sticker pack revolves around layering and instead of relying on the user to scale up each layered image I want to scale down the "base" images so the first image they place is smaller and all the layered stickers are correct matching size.