How can I make an either/or option for product attributes?

Hello,

I have a client who makes customized products. For most of the products, customers will have to choose whether they would like solid color vinyl or glitter colored vinyl. Right now, I have the solid and glitter colored options as two separate attributes. I want the customer to only be allowed to pick ONE of the two options. How can I make it so the customer is not allowed to pick from both options and is forced to only pick one? My client also sells shirts, so for those products I need the customer to pick their size and either a solid or glitter colored vinyl.

My client has too many solid and glitter options to be grouped into one attribute.

Thanks in advance!

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