Help!: Tile trim dimension quiery

[grimeyjim]

Hi everyone, newbie here! going to be adding extra tiles to existing ones in my bathroom.
One question about tile trims regarding the depth of the exposed area.
(please bear with me here!)
I want to match my new tile trim to the existing one.
My question is:
The measurement of the rounded exposed trim (when fitted) of my existing trim is 10mm (measured like a right-angle)
My new tile thickness is 9mm. So am I right in buying a 12mm depth trim?
Does the exposed part of the trim get bigger the more depth of trim you buy???
I hope this makes any sense to all you good people.
Many thanks
James

[whitebeam]

If you change the trim size it will noticable, has the new tile got a curved edge

[365drills]

I've read this a couple of times....

Are you asking: That you want to buy exactly the same tile trim that you already have in your bathroom. And because it is fitted (and you dont have any offcuts or spare) that you can't find an accurate way to find out if it is 9mm 10mm 11mm 12mm so you are trying to measure what you already have fitted in order to help you source the correct size?

(is that the question?)