Wednesday, July 6, 2011

Troubleshooting Paper Problems: When The Sizing Goes Bad.

Was rummaging through my old stuff and saw this discarded painting.  Perfect illustration for explaining stale sizing.

I have this habit of setting aside half-finished paintings when I get that feeling that something about it is off.  "Aha!" moments sometimes come when you've stopped obsessing over something.  Sometimes it would take me days or weeks before I would get back to a particular painting.  This one somehow worked its way to the bottom of my pile and I forgot all about it.  Almost a year has passed since I last touched it.  When I tried working on it again to finish it, spots started appearing wherever I wet the paper.

Reminded me of salt effects.  This one however, is caused by sizing gone bad.  We have touched a bit on sizing in a previous post.  (Watercolor Papers and Sizing).  But basically, the idea behind sizing or the addition of gelatin to watercolor paper during its production is to make the paper more workable with watercolor.  Sizing allows you better control over your watercolor as it decreases the tendency of the paper to absorb liquids and paints like tissue paper.  Between the paper pulp and the gelatin, the gelatin would be the first to go stale with old stock paper.  Signs of this would be the appearance of spots that don't go away after a wash or after an application dries.  Another would be when you discover areas that resist any application of paint you put down on it. 

There are several ways to hasten the deterioration of the sizing.  As demonstrated in this ruined painting, one way is by wetting a painted watercolor that has lain undisturbed for months.  You can also hasten the deterioration of new paper using the same principle.  The moment you wet a watercolor paper, its sizing gets disturbed. Maybe water acts as a catalyst.  This is the reason why you are advised not to stretch paper in big batches.  Stretch only what you think you will be able to use within 2 or 3 months.  That's just my estimate.  In our weather where heat can be more than the usual, it is always more prudent to stretch only what you think you will use.  The window of usability may be different in your environment and you should let experience guide you.  

A sign that this was not bad paper to begin with is how the undisturbed, previously painted part is free of spots.  Check the picture.  You wouldn't know that the paper's sizing has gone bad if you do not re-wet the paper.  When you find yourself itching to touch up a painting years after it is finished, remember what happened here.  
Not all old stock paper go bad.  I use Arches cold pressed watercolor paper in rolls.  One of the most economical way of buying paper is by buying it in rolls.  Because you cut to size, you minimize wastage of excess paper.  As long as you do not get the roll wet and observe proper storage, the paper stays usable for years.  Proper storage includes storing it in its original wrapping and in the box it came in and with the crumpled paper fillers still inside.  Do not put this container/box in an area prone to dampness such as near windows, bathrooms, basements. Also keep it away from direct heat or sun exposure so the paper inside does not get heat-baked.

You do need to recognize what stale sizing on paper looks like, specially when you like to take advantage of art supplies on sale.  Some stores put their older stocks on sale just to move the items and to make way for newer supplies. Some of these discounted paper will still be good for use but many might have sustained handling or storing damage.  For this reason I prefer to spend on paper and get new stocks.  You're not really saving on money if you get bad paper.  But sometimes good bargains are hard to resist so if you must, at least learn to discern the appearance of stale sizing to help you shop wiser.

I wonder if you can see the very pale yellow spots.  That is how spoiled sizing looks on paper that has never gotten wet.  Just turned bad over time.  (I keep samples of everything.)  But don't go hunting for spots where there are none. Even new paper looks a bit uneven because of how the lighting plays off against the hills and valleys of the paper.  The surest way to check is to wet the paper.

This is the same paper, now wet.  Some new paper may have this tendency but on a very mild scale and if the paper dries without any marks, your paper is still good.  For tips on how to minimize this tendency, check out my previous article Watercolor Papers and Sizing

There are times when you would come upon a defective batch of paper.  The best way is to contact the seller and if no action there, the manufacturer to see if you can get a replacement.  Might be wise for you to do a little sleuthing online to see if other buyers have been complaining about certain batches.  You will have a stronger claim if your paper is from the same batch.  But do not be too quick to blame the suppliers.  Sometimes we may be unaware that we are doing something that harms the paper.

You can artificially ruin the sizing of the paper by soaking it too long under water.  Prolonged immersion may be the culprit why some sizing coagulate in spots.  This used to happen to me when I was a beginner.  Thinking more is always better, I would leave watercolor paper soaking for as long as 20 or 30 minutes before stretching it.  The suggested submerging time is only a few minutes.  Only long enough for the paper fibers to get wet.  If you soak it too long, even before you staple it down, you can tell you've ruined the sizing by the appearance of slightly darker spots on your paper like in the sample above.

Also, not all paper that develop slight spotting when wet are damaged paper.  Even new and undamaged paper may develop these slightly darker spot discoloration when wet.  But these would tend to disappear as the paper dries.  If you can't tell any spotting on the dried, stretched paper, your paper is good to paint on.

That's it.  Thank you for reading. 


  1. Karen, thank you for a most informative posting! I hadn't heard or read a lot of that info. Very good to know!

  2. hi, my name is andre and i love art very much.
    i just visit your blog and find out that your blog about painting is very nice.
    i do also have a blog.
    my blog is about crafts and handmade things that maybe you also like.
    please visit my blog and leave a comment.
    perhaphs we can exchange link if you don't mind?
    i guess it will be good..

  3. Years ago I had some spotting. I concluded it was mold. How would you know the difference.

  4. Hi Kathryn, Andre and Mary. Thank you very much for taking time out to comment.

    Good question Mary. Stale sizing and molding are problems we get to encounter at one point or another.

    Molds usually appear when the paper has been subjected to prolonged dampness. While still alive, they take on the colors black, green or white and would look fuzzy. They may extend a millimeter or several from the surface of the paper. They die when you dry out the paper and specially when you subject the paper to sunlight exposure for several hours/days. They usually take on spotty or circular formations or would occupy all the still damp area completely. When completely dry, they powderize and parts or all of it may be dusted off the surface. Sometimes it stains the paper brown and sometimes (specially true with the small white variety) the paper may look pristine afterwards. However, there is no guarantee there are no lingering mold spores and so to reuse the paper might be risky. Once the surface becomes damp again, they will come alive. Damage is often on one side of the paper only.

    With sizing damage, it would be a through and through thing. Wetting the paper would bring out the hardened, shiny and yellowish spots that would show on both sides of the paper. Unlike with still good paper, these yellow spots don't disappear once the paper dries.

    There is yet another type of paper damage that resembles sizing damage. This may appear when you store the paper in an area where you have what we call here "bukbok". I'm looking for the english equivalent but that is a type of wood damage where you get small pinhole size damage on wood beams/cabinets. You get wood powder raining down and staining whatever surface it contacts with...paper, clothes, leather, etc. After the contact with the wood powder, the paper may develop yellowish brown spots over time. Alas, it is often goodbye paper as the stain will prove to be permanent. The discoloration is probably from it acidifying the paper where it lands.

    And yet still another type of damage. Contact with unfinished wood and non-acid free paper. These may result in spotting over time. Which is why it is recommended we store paper, both unused and painted on, in acid free wrappings or containers to protect them.


  5. it was really excellent post!
    thanks a lot for sharing with us.

  6. Thank you for this post. I've had this problem in the past but it was with cheap paper and I thought that was the problem but it probably was bad sizing.

  7. Thank you CPI and Nancy for taking time out to comment and for the appreciation.

    Nancy, it could be due to both. Some brands that offer cheaper paper may not be as strict with their quality control as their more expensive counterparts. It is just possible that they may overlook unevenly applied sizing which could result in spotting even with new paper. The sizing damage could also be the result of cheaper paper being less tolerant to soaking and stretching. Which kind of puts one in a dilemma when using it. If you don't soak and stretch and you like to use a lot of washes, you may end up with very buckled paper in mid work. But if you try soaking, you could end up damaging the sizing application. Also, with the cheaper paper, sometimes soaking or over-wetting results in paper fibers coming off when you try evening it out in preparation for stapling or taping.

  8. I have a batch of Arches paper where sizing has gone bad and it is more like a blotting paper now. As I have been sitting on the stock for a while and do not have a receipt, I cannot return it anymore. What is there to do please? Somebody told me to purchase Sizing Medium in art shop and paint it on the top surface, somebody else recommended Stabilising Solution purchased at a hardware store at a more economical price. Whichever way, I have nothing to loose. Would appreciate any feedback and advice. Thanks

  9. Hi Alena,
    With the rising cost of art materials, it is very tempting to try and salvage what we can from ruined stocks. Anything to help us stretch the buck is much welcome. I have not tried using sizing medium to correct ruined sizing on paper yet so I do not know if it works. There are several things to consider though. Sometimes, correcting something takes longer and costs more in the long run (time and effort + cost of materials you would use for the correction). It might be more economical to just buy new paper. Another thing to consider is will the addition of new sizing change the properties of the paper too much that it will behave very differently from what you are used to. You might have to adjust how you paint and this might cost you more time than it would normally take for you to finish a piece. Also, I think it will not lift or remove the sizing stain already on the paper. However, while the paper may not be fit for use with transparent watercolor anymore, it can still be used for the other watermedia like gouache and acrylic. Their opacity would be more suited for hiding the paper's flaws. Paper is still acid-free even with ruined sizing so the problem is more of cosmetic and how it affects the absorption of watercolors. Acrylics, which adhere to most surfaces and provides better covering power, might be best for the affected paper.

    You might also want to experiment with gesso. I've always wondered about yupo and other new painting surfaces like terra skin(rock paper) and how it might be fun to paint on surfaces that allow you to lift a color completely. Many of my favorite modern artists use yupo and some have already experimented with terra skin so naturally my curiosity is piqued. Since these new materials are not readily available where I am at, I got an advice before that I should try painting watercolor on gessoed paper to get an idea of how it would be like to paint on these modern surfaces (before I invest and order them from abroad). When I tried watercolor on gessoed paper, it was actually fun and you might like the effects you normally would not get from just painting on paper. You can even paint on gessoed paper with oil. The gesso acts as a barrier and preserver against acidity and oil damage. Gesso might be just the thing.

    Another idea is to use the paper for future mosaic paintings or collage projects. Paint on it with watercolor and take advantage of the "stains" to make more interesting color swatches.

    Thank you for taking time out to comment Alena. If you proceed with the sizing experimentation, I hope you post it also in your blog. I'm a follower now. Beautiful paintings. :D Am very curious how it would turn out.

  10. Hi Karen
    thanks so much for replying, sorry for responding so late....but had most awful few months after a foot operation.
    It has been recommended to me by the owner of my Art Store, who obtained it by getting in touch with his artwork restorer : spray all the paper with 50 : 50 solution of water/methylated spirit, then solution of methyl sellulose should be brushed on. I will be getting the MS powder from the art restorer. It is all time consuming, but so much paper has gone..I need to do something, cannot afford to feed the bin. I do not like acrylics or gouache, but I think your idea of gesso is also worth pursuing.
    Thanks once again for your input.
    I also appreciate your comment on my I mentioned before..I am an amateur & it is only in my little free time I can paint, it is my love, hobby and relaxation all in one.

    1. Hi Alena,
      Thank you for sharing this tip. If I can find the MS powder and the cellulose solution, I might try the experiment too. Very good for the art budget if we can save paper and paint.

      It is my pleasure to read your blog. Like you, I believe painting is its own reward. Earning from it is an added perk. I look forward to seeing more of your art. :D

  11. i just returned to watercolor painting after several years away. i had a large supply of paper and am distressed to find that every paper i have tried so far is acting like a blotter for the paint. so far i have tried waterford rough, arches rough, and strathmore. the paper just absorbs the paint like a blending, no mixing. i never imagined that paper could go bad. it has been stored in a dry, dark area in original packaging. i am very upset about this as i can't afford to replace it.

  12. Hi Samudra,
    Thank you for taking time to comment. So sorry to hear about your WC paper stock going bad. Watercolor papers are expensive and any loss of supply can be hard on the wallet. I think what happened to your paper is that the sizing has disappeared or gone to the point that it is now like tissue, absorbing the paint so rapidly there is no time to work the paint around. One cause of this could be soaking the paper too long or in my case, running the paper under water too long and mechanically agitating the surface too much. I have recently received some watercolor paper samples from a new company to try out. Not all WC paper are the same and each one requires time to get to know the characteristics of. I was trying out their 140 lb CP and did the usual stretching preparation I would do with Arches. I only realized my mistake when I started painting on it later. With Arches, the surface is very hardy that it takes a lot of abuse (from me). Even when I run my hands vigorously on the paper's surface while I have it under shower water to remove some of the surface sizing, this still leaves enough of the sizing for me to work with. With the new paper, moving my hands across the paper while it was under water eventually agitated the surface too much that it removed most of the surface sizing and roughed the surface up some. When I painted on it, my color passages instantly got diffused edges. It was like a semi-blotter. My colors also dried a lot lighter as the pigments had a tendency to go further into the deeper layers of the paper. I corrected by using less water on my paint and layering color. Anyway, once I have taken note of the difference needed with handling, I think my next try at stretching and painting on the new brand paper would be better. Thought to mention this just in case you may have tried my suggestion on removing the stale sizing with old paper. I hope you had not thrown the papers yet. Try experimenting with a shorter soak or wetting when preparing the paper. My suggestion on removing the surface sizing is more for correcting paper that developed sizing coagulation spots. If your stocks do not have these spots yet, there is no need to remove much of the sizing. Just wet the paper enough to allow you to stretch it effectively. Keeping more of the sizing intact would keep the pigments on the surface of the paper longer and it would be more workable too. Do not lose hope just yet. Try preparing another paper. Age could have altered some of the papers characteristics but with some adjustments, you might find the paper still workable.

    Another angle would be the paint you are using. It may not be the paper but the paint that is causing the problem. You said earlier that you have tried different brands of paper with the same result. I noticed that you have been using some of the best paper brands too for watercolor painting and it is unusual (though not impossible) that they all would give bad results. It got me thinking that maybe it is not the paper but the paint that could be causing the problem. Try painting with another brand watercolor. Different watercolor color brands behave differently from each other. I went through several brand sets of watercolor before finding the one that works for me.

    Good luck and thank you for sharing your experience. These help me a lot in learning about the medium and materials too.

  13. Has anyone had success restoring old arches paper that lost sizing? Gesso?

    1. Restoring sizing is a tricky question. Not all paper sizing can be lost, there is an internal sizing or gelatin mixed in the pulp when it is pressed and that is near impossible to restore because it is inside the paper when it was made. Surfave sizing can be enhanced by melting gelatin to warm water and applied in a brush. This is usually done by those who do transfer prints from films in the old process of lithographs. Results are not guaranteed and the effort is not worth it once paper seemed to be expired. I donot recommend it either.

  14. Nice article as well as whole site.Thanks for sharing.