Duplex and Triplex stocks. Why the thickest wedding invitations cost more

If you’ve spent an evening comparing wedding invitations online, you’ll have noticed something a little odd. Two cards can look almost identical on screen, and one of them costs twice as much. It’s a perfectly fair thing to be suspicious about.

More often than not, the difference isn’t in the design at all. It’s in the paper, and specifically in whether that paper has been duplexed.

What duplex and triplex actually mean

A duplex stock is two sheets of paper bonded together to behave as one. A triplex is three. That really is the whole idea, though what it does to a card in the hand is rather lovely.

Our Aurora Rose invitation is a good example. It’s built from Wild Cotton Natural White 300gsm on the face, bonded to a 300gsm deep blue on the reverse. Two ordinary sheets become one 600gsm card, with a soft cotton front, a dramatic blue back, and a stiffness you notice the moment you pick it up.

You might wonder why we don’t simply order thicker paper. The honest answer is that paper mills can only make a single sheet so thick before the fibres stop behaving. Past a certain weight, a sheet turns brittle, cracks when it’s scored, and becomes very difficult to feed through a press. Duplexing sidesteps that limit entirely, because every layer is still a thin, well-mannered sheet right up until the moment it’s bonded.

How it’s actually done

Let’s get a little technical, because this is where the cost comes from.

We produce our invitations with Stitch Press, an Australian specialist whose duplexing and letterpress work is among the best in the country. The order of operations is the part most people find surprising: the printing happens first, and the bonding second.

1. Each layer is printed on its own. Letterpress, foil and embossing are all applied while the sheets are still thin enough to take a deep, clean impression.
2. The paper grain is matched. Both sheets need their grain running the same way. Get this wrong and the finished card will bow within days as the layers expand and contract against one another. It’s the most common way duplexing fails, and the main reason this work belongs with a specialist.
3. The adhesive goes on evenly. A thin, consistent film. Too much and it bleeds at the edges or ripples the surface; too little and the layers part company months later.
4. The sheets are pressed and left to cure. Bonded under even pressure and dried flat under weight. Rushing this is how you get warping, and in an Australian summer the cure takes longer than the calendar would like.
5. The card is trimmed last. Guillotined after bonding, never before, so the edge reads as one clean face rather than three layers with a visible seam. This is precisely what separates a properly duplexed card from a glued-together one.

The colour core, and why couples fall for it

Triplex has one lovely variation worth knowing about. The middle layer doesn’t have to match the outer two.

When the card is trimmed, that middle sheet shows as a fine stripe of colour running around all four edges. Our Elizabeth invitation is the clearest example we make: Wild Cotton Natural White 300gsm on the front and back, with a Koehler Euler Eco Black 350gsm core between them. The result is a 950gsm card with a black line framing every edge, and gold foil sitting on a warm natural white face.

It’s a detail nobody thinks to ask for, and one that everybody notices. Because the core is the paper rather than a coating, that edge can’t chip, scuff or wear away, which isn’t true of painted or foiled edges.

Why thickness matters for the printing itself

The weight isn’t only decorative. It’s doing real structural work.

Deep letterpress needs somewhere to go. A letterpress plate physically presses into the paper. On a single sheet, that impression shows on the reverse as an unsightly bruise. Bond a second sheet behind it and the back stays perfectly flat.

Embossing and debossing work the same way. The Aurora Rose carries a blind debossed rose and letterpressed names in a Pantone colour, both pressing into the card. Without that second layer behind them, the pressure would telegraph straight through.

Foil simply sits better on a card with body. A foil monogram on flimsy stock reads as a sticker. On a 950gsm triplex, it reads as a seal.

Duplexing can also save you money

Here’s the part that tends to surprise couples: duplexing isn’t only a way to spend more.

Our Kathleen invitation uses two sheets of Gmund Matt Midnight Blue 300gsm bonded into a 600gsm card, then printed digitally in opaque white ink. There are no letterpress plates and no foil dies, yet it still has the presence and stiffness of a far more expensive invitation.

Weight and specialty printing are separate decisions, and if your budget only stretches to one of them, we’d gently suggest you choose weight. Your guests feel the card before they ever examine the printing.

Which pieces are worth it

Not everything in your suite needs to be duplexed, and we’ll happily tell you so.

It earns its place on your main invitation, which is the piece guests hold, pass around and pin to the fridge. It’s lovely on save the dates, where you want the first impression to set expectations for the day. And it works beautifully on menus and place cards, where a triplex colour core repeats across every table and quietly ties the room together.

It’s less worthwhile on RSVP cards, which get posted back and need to stay under a postage threshold, and on detail cards, where a single sheet in the same stock reads as considered rather than cheap. That contrast actually makes your hero piece feel more special.

You certainly can duplex an entire suite. It’s also the quickest way to spend your budget without increasing its impact.

So why does it cost more?

There are three honest reasons, and none of them are us taking a bigger cut.

The materials multiply. A triplex card uses three times the paper of a single sheet, and on a premium cotton the stock alone is a real line item before anything is printed.

The labour is slow and manual. Bonding, aligning, pressing and curing are hands-on steps with genuine drying time between them. There’s no machine that makes this fast, and it’s a large part of why our duplex and triplex designs carry a four week production window after you approve your artwork.

The wastage is higher. Every additional layer is another chance for misalignment, glue bleed or a warped sheet. Cards that don’t cure flat are scrapped, and that loss is priced in.

What you’re really buying is permanence. Almost everything else you’ll spend on is consumed on the day itself. The flowers wilt, the food is eaten, and the venue is handed back on Sunday morning. Your invitation is one of the very few things that outlives the wedding, and it will still be in someone’s drawer in thirty years.

Weight is the shorthand for all of that. It’s the difference between something printed and something made.