# How does a "juice deck" work?

**URL:** <https://boards.straightdope.com/t/how-does-a-juice-deck-work/677497>\
**Category:** The Game Room\
**Created:** [December 30, 2013, 6:48pm UTC](https://boards.straightdope.com/t/how-does-a-juice-deck-work/677497 "2013-12-30T18:48:00Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\
**Post date:** [December 30, 2013, 6:48pm UTC](https://boards.straightdope.com/t/how-does-a-juice-deck-work/677497/1 "2013-12-30T18:48:00Z")

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I have a number of books on gambling scams and cheating, and several mention the “juice” method of marking cards as being a nearly perfect technique. However, most were written at the time the technique was in first wide use and thus highly confidential among grifters and sharps.

Googling around now, I see you can buy juice and an instruction booklet for around $50.

Does anyone know what “juice” is and how it’s used to mark cards?

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**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\
**Post date:** [December 30, 2013, 8:18pm UTC](https://boards.straightdope.com/t/how-does-a-juice-deck-work/677497/2 "2013-12-30T20:18:27Z")

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From what I understand, a “juice deck” is marked in such a way that you only see the mark if your eyes are unfocused.  
edited to add: In other words, it isn’t the deck that is juiced-it’s the sharp! 😃

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**Author:** ![Kobal2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kobal2/32/20_2.png) [@Kobal2](https://boards.straightdope.com/u/Kobal2)\
**Post date:** [December 30, 2013, 8:28pm UTC](https://boards.straightdope.com/t/how-does-a-juice-deck-work/677497/3 "2013-12-30T20:28:43Z")

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Well, you know the juice. Prob’ly mark the deck with a menorah or a dreidl or somesuch.  
What ? What did I say ?

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**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\
**Post date:** [December 30, 2013, 8:47pm UTC](https://boards.straightdope.com/t/how-does-a-juice-deck-work/677497/4 "2013-12-30T20:47:19Z")

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> [@Czarcasm](#):
>
> From what I understand, a “juice deck” is marked in such a way that you only see the mark if your eyes are unfocused.

Right, I know how it works in a functional sense; what I want to know is (1) how does it work in a technical sense and (2) what is the “juice” compound?