Changing product options after publishing

Site URL: https://www.thelightexplorer.com/

Hey guys,

I just created my online store (https://www.thelightexplorer.com/) and had an issue. If you go to the shopping section and then choose a product, you see a dropdown option for 'Material'. This is for all my prints. I now need to amend the text to add 'Unframed' before the options - so the dropdown choices now will be:

Unframed Photographic Print

Unframed Metal Print

I was hoping there was a short way to do this (rather than edit each individual product and then type it in). Given that the same Material options are being used across all products, is there any way to do it in one go?

Thanks so much,

Nikhil