Can Watercolour Paper Deteriorate?

If you've pulled out a beloved pad or big sheet of watercolour paper only to find it's soaking up paint like a sponge, don't panic. You're not alone, and it's probably fixable.

Watercolour paper, whether cheap or expensive, cotton or cellulose, can deteriorate over time. There are two main culprits worth knowing about.

1. The first is chemical and/or biological damage. Acids from household cleaners, food smells, vinegar, even alcohol can drift through the air and quietly degrade your paper. Moisture give the opportunity for mould or algae, attracts insects or animals to stop by and snack. You'll usually notice yellowing, dark patches, tears, crumbling or even holes. Unfortunately, this kind of damage is pretty much permanent. there's not much you can do to rescue it. If this is effecting existing art work, especially if its precious, don’t attempt to fix it yourself seek out professional conservators. There are ways to improve the storage and display that can halt further deterioration.
2. The second culprit, the more common one, is the sizing breakdown. Sizing is the term used in paper making circles that refers to any substance added to or applied to the surface to reduce the absorbency of water. Most quality watercolour paper is coated with gelatine, the same stuff that makes jelly set. It's brilliant for painting because it holds moisture and pigment at the surface rather than letting them bleed deep into the paper. The problem is that gelatin is sensitive to humidity, temperature fluctuations, and light exposure. Humid environments or climates are particular culprits, but even leaving your pad on the back seat of a hot car can cause it to fail in patches. The result? Your paper suddenly behaves like blotting paper.

The good news is there are ways to bring sizing back. The simplest fix for the more expensive papers that will have both internal and external sizing is to wet the entire sheet, let it dry completely, and paint on it straight away. You can add the desired level you require in that new painting session. It sounds almost too easy, but it genuinely works, there are plenty of experienced painters who swear by it. The catch is you really only get one go at this, so time it well.

If that's not enough, you can re-size the surface entirely. Powdered gelatine is one option, though it's a bit fiddly. A more practical route is using a commercial watercolour ground.

I have found acrylic gesso also works well. Thin coats work best, I aim for two light layers, keeping the water content below about 30% to avoid bubbling and poor coverage. The dilution allows better flow/coverage and also gives you control over absorbency. More water leads to more absorbency, so a bit of experimentation and you can get back to something close to the original paper feel.

One tip worth trying: instead of a brush, use a small foam roller to apply the gesso. It leaves a fine, even texture similar to cold-press papers that's genuinely lovely to paint on. Especially if you're working with granulating pigments that like to settle into small dips and hollows.

So before you throw out that dodgy paper, give it a second chance. Chances are, it's not as far gone as it looks.

From Frustration to Innovation: Saving a Watercolour Painting Gone Wrong

As artists, we often stumble upon unexpected challenges that lead to creative solutions. I want to share a recent experience that turned a potential disaster into an interesting experiment with old watercolour paper and ground.

Lately, I've been on a mission to use up my old/unused art supplies – particularly my watercolour paper stash. During a recent Wednesday Wanderers session, I pulled out what I thought was my trusty Bockingford paper, a brand I've always appreciated for its forgiving nature. Oh, how wrong I was!

The Problem

As soon as I began applying my usual semi wet-on-wet technique for the background, I knew something was off. Instead of the familiar behavior I expected, the paper acted more like blotting paper – greedily soaking up every drop of pigment. The whole sheet remained stubbornly wet throughout the entire session. Even after drying, the paper was noticeably warped.

I suspected this must have been a forgotten sheet from an ancient pad, likely suffering from deteriorated sizing. But rather than consigning my work to the bin, I saw an opportunity for experimentation.

The Solution

Remember that watercolour ground I'd recently purchased for the VAS 9 by 5 exhibition to paint on wood? That became my saving grace. I decided to apply two very light coats to the troubled paper. While this process did lift some of the original colour (an expected side effect). 

The improvement in the paper's surface was remarkable.

The Result

The experiment proved successful! The watercolour ground not only rescued my painting but also gave the paper a second life. It's fascinating how often our artistic "mistakes" can lead to discovering new techniques and solutions.

Key Takeaways:

• Don't be too quick to discard "failed" paintings

• Old art supplies might surprise you (not always pleasantly!)

• Watercolour ground isn't just for wood – it can rehabilitate problematic paper too

• Sometimes the best discoveries come from trying to fix our mistakes

Has anyone else experienced similar issues with aged watercolor paper? I'd love to hear about your creative solutions to art supply challenges!

Originally shared on Instagram.