Tuesday 14 March 2017

How much does size really matter?

No, I don't mean men's willies, I mean size as in sizing on/in watercolour paper!

When paper is manufactured, sizing is added to reduce how much water the paper will absorb. Unsized papers are basically kitchen paper and so on - very absorbent and of course useless for art. Drawing papers are slightly sized ("slack sized") and have a bit of resistance to water, but watercolour papers are much more "hard sized" to make them very resistant. Now, within watercolour papers, we often refer to some as "hard sized" to mean "very hard sized" whereas the weaker sized watercolour papers are still "hard sized" in the context of all types of paper.

When paper is being put together, sizing can be added to the pulp, which results in "internal sizing", or, onto the surface ("surface sizing" - the latter is the much more water repellent form of paper.

In this video, I compared the following - the manufacturers are indicated as follows:
[DR] = Daler and Rowney
[SCM] = St Cuthbert's Mill
[C] = Canson
Chemical Pulp:
Aquafine Hot Press. This is a fairly low-end student-grade paper, which I only use for swatching normally [DR].
Optima This is not a watercolour paper - it's a mixed-media paper that I just added for a bit of a laugh really to see how it performed [DR].
Bockingford Cold Press. This is a very good paper that I use day-to-day [SCM].
Langton Rough. This is again, a decent day-to-day paper [DR].

Cotton Rag:
Langton Prestige Rough. This is a generally good paper that is a very good entry-level-to-cotton-papers paper, for people who are moving up from chemical pulp papers [DR].
Saunders Waterford Cold Press. This is pretty hard-sized and a very high quality paper [SCM].
Arches Cold Press. This is quite hard-sized but ultimately no more so than Saunders Waterford [C].
Millford Cold Press. This is almost an "extreme sized" paper, with a very strong surface sizing. There is nothing else like this  on the market [SCM].

I did my tests using French Ultramarine by Winsor & Newton in one of their large pans - these are VERY economical and well worth having for the colours you use the most:

Amazon USA No stock at the time of writing.
Amazon UK £20.99 £15.10
Amazon Canada No stock at the time of writing.
Jackson's £20.99 £13.64


  1. I have recently become a fan, and you don't need to answer this comment -- keep painting! (Since I discovered you, I have spent a lot of time literally watching paint dry -- on YouTube -- in the past two weeks!) I appreciate your attention to paint chemistry -- and I am distressingly down to the last squeeze of my original W&N New Gamboge! Will be searching for your advice -- which I forgot to write down while watching. This post on paper sizing was timely -- I had just spent my morning re-reading a very good, detailed discussion of sizing in a 30 year old magazine: Watercolor 87, an American Artist Publication. It included a chart comparing about 50 papers from many countries -- but it is obviously out of date. In the U.S., Arches and Fabriano are widely used artist papers -- so, if you run out of topics, a comparison of those two would benefit your American fans. Personally, I like the sizing on Arches; I do a lot of glazing. Fabriano has changed product lines (and confuses the issue with "Soft Press" in addition to Hot, Cold and Rough.) I like other people's work on hot pressed papers, but doubt is it for me. The question of sizing and the way the water sits on the paper seems to also be affected by press/paper finish and by weight (300 lb isn't just thicker, according to many who love it; some say is remains wet longer, others that is lifts better....) I hope you get a chance to experiment with Arches and Fabriano on camera. I find that even visiting the manufacturers' websites doesn't always tell me what I want to know about sizing: internal? external? both? -- although I did discover that Fabriano does not use animal products/gelatin.) I'll stick with Arches 140 CP 140, which I haven't had to stretch, so far. (I'm quite good at flattening paper that wants to curl before framing it -- possibly aided by my seaside humidity.) If you are ever "gravelled for matter," another topic that might help painters on a tight budget is a discussion of painting size and available pre-cut mats. (I've been compiling a list.) Beginners tear a 22 x 30 inch sheet into four 11 x 15 sections -- not realizing that, if they fill one with their composition, they will have to have a mat cut to order -- or crop off part of the picture, which would be maddening if their composition was carefully planned. I was trying to mat and frame my work for sale, and after cutting a lot of mats during the week before every show, I finally went out and bought pre-cut archival quality mats in several sizes, which I use to lightly indicate "actual size" in pencil on my blank paper before I start painting. That solves the question: "Does this mat overlap the picture by 1/8 inch or 1/4 inch all around?" This seems petty, but one inch can mean the difference between paying for a 16 x 20 inch frame or a 20 x 24, a difference which has to be added to the price of my picture -- which may not sell. Sorry to ramble on -- but I am really appreciative of your approach. Thanks!

    1. Tbh most artists cut their own mats as it's far cheaper - so standard sizes honestly don't matter. It takes minutes and costs $10 for the means to do it and it's very, very easy to learn to do.

      The higher weight papers are just thicker and because they are, there is more room inside for the water to move, so the surface stays damp a long time but doesn't pool like thinner papers do. If a thin paper is over wet, it pools, if under wet, it dries too fast. Thick papers don't pool unless drenched but DO dry nice and slowly so if underwet they retain moisture.


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