Silver and Black Border Explanation

So mark people keep saying to you UB Should be silver borderAnd you say silver border cards can't be made into black border.I think they refuse to believe because of cards like “Target Minotaur” with “Lightning Visionary” pretty much exactly the sameAnd “Super-duper death ray” to “Flame spill” which is the same but trample part is removed.Can you explain your statement with these cards in mind?

The purpose of silver border is that it’s for cards that can’t work in black border. To help simplify Unstable limited we made a few simple creatures that we loosely justified with an art variance. Super-Duper Death Ray didn’t work in black border at the time Unstable was made by a Rules Manager figured out how to do it afterwards. Silver border was never intended as a way to take cards that work perfectly in black-border Magic and make them off limits. It was a border to allow us to print cards that otherwise couldn’t be made. I will note as Magic evolves some things we formerly couldn’t do in black border become doable as with Super-Duper Death Ray,

Art Black Border Card Printing Creatures Flame Spill Lightning Visionary Limited Minotaur Rules Manager Super-Duper Death Ray Target Minotaur Trample Un-Magic / Silver Border / Acorn Un-sets