Tyvek Himber Envelopes are great utility poker card size, double sided himber envelopes, brown color, made in very durable tyvek material.
They are made for switching and multiple outs:
- Switch any freely chosen card into your force card
- Use any two force cards and reveal either one as your prediction
- Use two double face cards in one envelope to have four possible outcomes
- Use any blank card with any words, symbols and numbers for the above applications
I use two of them in my magnetic Himber wallet and there are four outs but spectator sees one envelope and one card.