Should I go with aluminium or steel plates ?
Never use aluminum metal for storing anything important including seed words.
This metal is much weaker and it can be deformed very easy, it has much lower melting point than stainless steel, copper, titanium and similar metal alloys.
Best price ratio is using stainless steel metal plates or washers for this purpose.
Wouldn't it be a risk if I give my keys to the vendor to engrave it on the plates ? What if he steals my coins?
Also, If I don't give the words to the vendor how will he engrave it ?
Never give your seed words or keys to anyone, and don't send them to any websites and cloud.
It's better to use regular pen and paper, or buy simple tools for writing on metal, this is not expensive at all.
One solution that I can think of is to find 3-4 similar vendors and give a few words to each of them to engrave on the plate
Forget about it.
It's to complicated and risky.
