Should be an old, beat up deck of cards with obvious wear. OK if it’s missing a few (up to 6 missing).
Put another untapped deck in the junk drawer in case someone wants to actually play cards.
Discussion
When traveling by air, use an airline branded deck for extra opsec. Use ordinary bicycle cards if traveling by other means.
If discovery is immanent, take the deck out and shuffle it, or drop/scatter the cards to destroy the seed.