This isn't really a close comparison, and it's worth saying plainly: a kitchen Ziploc bag was never engineered to touch a collectible for years at a stretch, and using one anyway is a common beginner mistake worth correcting early.
Why a Ziploc bag falls short
Standard kitchen plastic isn't acid-free, and it isn't designed to let moisture escape. Sealed against a card long-term, that combination can trap condensation against the surface and contribute to the kind of slow damage that doesn't show up until it's already done.
What a team bag does instead
A real team bag is made from crystal-clear, acid-free, archival-quality polypropylene, built specifically to sit against a card without reacting to it. It still seals with a resealable adhesive strip, so it's no less convenient at the point of use, and it costs a few cents more per bag at volume.
The one place a Ziploc bag is fine
Short-term sorting on a table, for a few hours, isn't going to damage anything. The risk is in what actually gets stored in one long-term, and a common beginner mistake is not moving cards out of the sorting bag into real storage before they sit for months.
Shop team bags on Amazon → (paid link) See our sorting system →