Bar coasters get ordered by the ten thousand off a price per unit and judged by whoever sweeps up. These four checks close the gap.

Ask for two board numbers, not one word

Grammage is how much board there is by weight; caliper is how thick it is. A compressed board and a bulky one can weigh the same and behave completely differently under a wet glass.

‘Standard’ and ‘premium’ are price tiers. Numbers are a specification.

Ask which way the grain runs

A mat only gets wet on the top face, so it swells on one side and cups. Grain direction is most of what decides how far it goes.

It is a free thing to get right and almost nobody is asked for it.

Check the cut edge

Run a fingernail round the rim. A clean, compressed edge means a sharp die on the right board. A furred, fibrous one means neither, and it will look worse by the second round.

This is the cheapest quality signal in the whole product.

Then use the back

The reverse of a coaster is the best-read surface in a venue: close range, willing reader, time to spare. It is also usually blank.

Design the two faces as two different jobs and one mat does the work of two placements.

Finally, buy against a file

Board, grain, inks, coatings and PMS held on record is the only thing that stops a caliper quietly thinning between pallets.

The product is simple. Buying it well is a spec sheet, and now you have one.