Mystery Borders contain eligible rare and super rare border types. Here are the following eligible and ineligible border categories:

Eligible: 

• Rare and Super Rare Neon
  • NeonWhite
  • NeonYellow
  • NeonBlue
  • NeonGreen
  • NeonPurple
  • NeonRed
• Super Rare Cosmic
  • CosmicGold
  • CosmicGreen
  • CosmicOrange
  • CosmicPink
  • CosmicBlue
  • CosmicRed
• Rare and Super Rare Metallic
  • Metallic Copper
  • Metallic Silver
  • Metallic Gold

Ineligible:

• All Holiday related borders
  • SnowflakesRed
  • SnowflakesBlue
  • WrappingPaper
  • CandyCane
  • IceBlue
• Ultimate Cosmic
  • CosmicBlack
  • CosmicRainbow
• All Web
  • WebBlack
  • WebRed
• All Promo
  • MatteRed
  • MatteBlack
  • DistressedRed
  • DistressedBlue

Odds of pulling each rarity type are as follows: