Why Filler-Free Watercolors Handle Differently

At Gapka, we don’t use fillers in our watercolors. That changes everything.

Many commercially manufactured paints include additives like chalk (precipitated calcium carbonate), dextrin, or other “extenders.” These aren’t necessarily evil, but they do change how paint behaves. Their job is to bulk up a formula, adjust flow, or reduce pigment costs. Ours is to let the pigment shine.

What Fillers Do (And Why We Leave Them Out)

Fillers soften a color’s intensity. They can reduce granulation, increase opacity, or make a paint feel “smoother” coming out of the pan. But that smoothness often comes at the cost of personality. You lose the edge. You lose the unique behavior and voice of the pigment and at Gapka we want each pigment to speak for itself.

By skipping fillers, we preserve the natural characteristics of each pigment:

• Some bloom with subtle granulation.
• Some strike the paper boldly and settle fast.
• Some lift easily, others stain with intention.

These aren’t flaws. They’re features.

How It Affects the Way Our Paints Feel

A filler-free paint behaves differently in the pan and on the page:

• More color per brushstroke. Our paints are packed with pigment. You’ll likely need less paint and more water. You'll also be able to paint with deep, rich colors like you may not have experienced before.
• Individual textures. Some colors might feel softer or stiffer in the pan. That’s because different pigments absorb binder differently.
• Real variation. A pan of Ultramarine will never feel like a pan of Phthalo Blue. They’re not supposed to.

The Trade-Off (If You Can Call It That)

Without fillers, some pans might shrink more or crack a bit as they dry. Some colors rewet more slowly than others. That’s all normal. It’s what real pigment, honey, and gum arabic look like without anything in the way.

We hand-pour and dry our paints slowly in multiple layers to minimize those quirks and we add a little dab on top to make sure that beautifully imperfect pan is full of the good stuff.