Double thick on flat pieces
Duplex is two sheets bonded into one — the answer whenever a flat piece needs an impression on one side and a clean face on the other.
Bonding two sheets gives you a caliper no single sheet reaches, and it gives you two independent faces. A letterpress or emboss bite lands in the first ply and never reaches the second.
It also unlocks a coloured core: a dark seam running between two pale faces, visible only on the edge. On a postcard that edge is the part someone sees first as it comes out of an envelope.
Duplex adds weight, and weight can change your mailing class. Confirm the class before the stock is ordered.
Duplex is heavier and stiffer than it looks. It does not fold without a deep score, and it can push a mailer into a higher postal class.
Looking for cards rather than flat pieces? Thick business cards.
Double thick — questions we get
- Why duplex instead of one thick sheet?
- Two faces. A single thick sheet still carries the impression through; two bonded plies keep side two flat, and let you run a different colour or texture on each face.
- Can a duplex piece be folded?
- Only with a deep score, and even then it wants a generous radius. For a folded mailer, a single heavier sheet usually behaves better.