I think letterpress papers have three characteristics (aside from color):
Thickness, Texture, + Heft
Heft is a combination of stiffness and weight. It’s an important characteristic, for sure. So is texture – some textures just play nicer with some designs.
But, far and away, the characteristic most people care about is thickness. And I’m here to tell you this:
[bctt tweet=”Most of what you know about paper weights is useless.” username=”afinepress”]
Describing a paper by its weight is of very little use to you. It’s a number that might mean something to commercial printers, but even that’s a stretch anymore. The way those numbers are derived is almost arbitrary. The number is derived from the weight of the “standard” number of sheets cut to the “standard” size.
Paper Weights Are Inconsistent
I put those words in “quotes” because there isn’t really a standard. Depending on how the paper is classified (cover weight, text weight, bristol, etc), the size of the sheet used as a “standard” is different. That means that, literally, just by calling a paper a different designation, the weight of the paper changes! That’s crazy! Neenah has a nice little chart that demonstrates this.*
Paper Weight ≠ Paper Thickness
Simply put, some papers are denser than others. That means that two different papers with the same basis weight can have drastically different thicknesses. It’s a fairly simple concept people rarely talk about.
So How Thick is That Letterpress Paper, Anyway?
There is one consistent way to measure and discuss the thickness of a paper: caliper.
Caliper is literally a measurement of the thickness of something using calipers.
Why didn’t someone tell us this from the start?!
The thickness of paper is measured in thousandths of an inch. It’s also called point size (there’s also printer’s points, which is a different scale, just to throw us all off).
So, we describe a paper like Crane’s 220# Lettra as being 42 pts thick. That’s 0.042″ or forty-two thousandths. There are a few ways to say it, but it’s a consistent measurement.
Look! A Chart!
And here’s a chart of several of the leading letterpress papers with their weights and caliper.
There are a few instances where papers that weigh less are thicker – that’s a density/heft thing. So, by weight, you may think you’re getting a thicker paper only to discover it’s actually quite thinner than a heavier paper!
You can see why Crane Lettra is a very popular paper – it’s the thickest of the “standard” papers – the three that are thicker are much more expensive and uncommon.
You can find the caliper of most papers, even if the mill doesn’t readily supply it by searching the paper name + “caliper.”
It’s one of the most sought-after characteristics of letterpress; I think the information should be more easily accessible.
*A more consistent way to discuss the actual weight of paper is grams per meter squared, or GSM. This number describes the weight of a single sheet 1 meter in height and width.