About Cold Press and Hot Press Watercolor Paper (and More)

My "First" Watercolor on Arches Cold Press
Watercolor Paper, 300 lb.

After learning a little more about this myself, I thought I’d share information on the subject that many new and aspiring artists may find of interest, too.

What do the terms hot press and cold press refer to and what do they mean?

We’re talking paper here, and while not exclusively related to watercolor, the terms are usually used in the context of choosing a paper for that medium.

I'm no expert on the subject by any means, and there is a whole lot to learn and know about the paper(s) that artists use for their artwork—much more than can be covered in today’s blog. However, if this is something in which you have an interest, there is plenty of information out there in cyberspace for you to Google, so have at it.

First, a brief, brief overview of paper-making, which is summarized from the site, Paper University. Paper is primarily made from trees, which have cellulose fibers that are processed into paper. This is done by making pulp from wood chips, dehydrating the pulp on screens, and then heating and drying it on hot rollers or molds until, voila!, it turns into paper. A lot of fine art paper is also made from cotton, which I assume is a similar process. Paper can also have a coating applied, such as clay or polymer.

That said, here are a few of the hard, cold (and hot) facts on the subject I gleaned from the internet, on such sites as Watercolorist’s Answer Book:

• There are actually three types: cold press, hot press, and rough.
• The difference among the three has to do with the resulting texture after the paper-making process.
• Cold press paper has a good bit of texture (or “tooth”)—a good memory jogger is to think goosebumps for cold press.
• Hot press paper is relatively smooth—memory jogger-think about melting relative to hot press; a melted substance is smooth.
• Rough paper is really rough, even compared to cold press paper.
• Cold press is used for a wide variety of watercolor effects from washes to detail work.
• Hot press is primarily used for detail work due to its smooth finish.
• Beware, the texture of paper can vary from manufacturer to manufacturer—what’s considered smooth for one may be toothy by another—so you have to experiment.
• Paper is categorized and sold by weight (or thickness) in pounds (lb.) or grams/square meter (gsm).
• I did not know this!--what's referred to as the weight is actually the weight of 500 sheets (aka a ream) of that particular paper—you could drop this into a conversation and actually sound knowledgeable about the subject.
• The "standard" weight for cold press paper is 140 lb/300 gsm. and 300 lb/640 gsm.
• The "standard" weight for hot press paper is 140 lb/300 gsm.
• Paper is sold by the individual sheet or in blocks similar to a tablet but bound together.
• The "standard" sheet size of watercolor paper is 22 x 30 in/56 x 76 cm.

So there—in a nutshell, everything you need to know about watercolor paper.
Cheers!