Card backs are a type of cosmetic item in Bloons Card Storm cards in a deck. During a match, card backs are visible while a card is being played and in the opponent's hand. If a player uses Expert Negotiator on a tower, then uses Return to Sender on that same card, they will have the card back of the opponent for that card specifically.
Card backs were not individually named until version 2.0.
List of card backs
Image
Name
Source
Introduced
Standard
Unlocked by default
Launch
Quincy Master
Level Quincy up to level 10
Launch
Gwen Master
Level Gwendolin up to level 10
Launch
Obyn Master
Level Obyn Greenfoot up to level 10
Launch
Amelia Master
Level Amelia the Amazing up to level 10
Launch
Adora Master
Level Adora, High Priestess up to level 10
Version 2.0
Exclusive Obyn Card Back
Purchase the Obyn Hero Bundle from the Store
Launch
Exclusive Amelia Card Back
Purchase the Amelia Hero Bundle or Amelia Mega Bundle from the Store
Launch
Exclusive Adora Card Back
Purchase the Adora Hero Bundle from the Store
Version 2.0
Founder Pack Card Back
Purchase the Founder's Pack from the Store (no longer obtainable)
Launch
Holiday Pack Card Back
Purchase the Happy Holidays Pack from the Store
Version 2.0
Ranked Season 1 Card Back
Tier 3 Ranked season rewards
Version 2.0
BCS Early Tester Card Back
Distributed as a gift to all players who registered for either of the beta tests (no longer obtainable)
Launch
Unnamed
Unobtainable (appears to only be accessible to Ninja Kiwi staff)[ 1]
Version 2.0
Gallery
Deck icons
Standard
Quincy Master
Gwendolin Master
Obyn Master
Amelia Master
Adora Master
Exclusive Obyn Card Back
Exclusive Amelia Card Back
Exclusive Adora Card Back
Founder Pack Card Back
Holiday Pack Card Back
Ranked Season 1 Card Back
BCS Early Tester Card Back
Unnamed Ninja Kiwi card back
Card icons
Standard
Quincy Master
Gwendolin Master
Obyn Master
Amelia Master
AdoraMaster
Exclusive Obyn Card Back
Exclusive Amelia Card Back
Exclusive Adora Card Back
Founder Pack Card Back
Holiday Pack Card Back
Ranked Season 1 Card Back
BCS Early Tester Card Back
Unnamed Ninja Kiwi card back
References
Navigation 
Standard
Quincy Master
Gwendolin Master
Obyn Master
Amelia Master
Adora Master
Exclusive Obyn Card Back
Exclusive Amelia Card Back
Exclusive Adora Card Back
Founder Pack Card Back
Holiday Pack Card Back
Ranked Season 1 Card Back
BCS Early Tester Card Back
Unnamed Ninja Kiwi card back
Standard
Quincy Master
Gwendolin Master
Obyn Master
Amelia Master
AdoraMaster
Exclusive Obyn Card Back
Exclusive Amelia Card Back
Exclusive Adora Card Back
Founder Pack Card Back
Holiday Pack Card Back
Ranked Season 1 Card Back
BCS Early Tester Card Back
Unnamed Ninja Kiwi card back
