Are clear sleeves legal in Riftbound?

Ruling: Clear sleeves are not legal. The back of your cards must have an opaque sleeve on the outside.

Nuances:

• Clear inner sleeves are allowed as long as the outer sleeve is opaque
• All cards in a deck must be sleeved alike
• Opaque inner sleeves with clear outer sleeves may be problematic because imperfections in the inner opaque layer would be difficult for a judge to see