Watercolour vs Acrylic for Paint by Numbers: Which Paint Is Right?

If you have ever opened a paint by numbers kit and wondered why the paints are acrylic rather than watercolour, you are not alone. Both are water-based, both clean up easily, and both are widely available in the UK. So why does every serious adult paint by numbers kit use acrylic, and what would actually happen if you tried watercolour instead?

This guide answers both questions directly, then walks through the key differences between the two mediums so you understand exactly what you are working with every time you open a kit. If you want to go deeper on the paint itself, read our full guide on what paint is used in paint by numbers.

Acrylic paint on the left covers the numbered canvas lines completely, producing bold, vibrant colour. Watercolour on the right leaves the printed outlines visible through the translucent paint.

Watercolour vs Acrylic for Paint by Numbers: The Direct Answer

This is not a matter of preference. It is a question of how each paint interacts with the surface. A paint by numbers canvas has printed numbers and dividing lines across every section. The paint you apply needs to cover those markings completely so that the finished painting looks like a continuous piece of artwork rather than a numbered diagram with colour washed over it. Acrylic does this. Watercolour does not.

Why Acrylic Works on a Paint by Numbers Canvas

Acrylic paint contains pigment suspended in an acrylic polymer medium. When it dries, the polymer locks the pigment in place on the surface as a solid, opaque layer. This gives acrylic three properties that make it ideal for paint by numbers.

• Full opacity: A single coat of acrylic covers the printed numbers, lines, and canvas texture beneath it. You paint over a section, and the markings disappear completely, which is exactly what you need.
• Fast drying: Acrylic dries to the touch in minutes. This means you can paint a section, move to an adjacent one, and come back without any risk of the colours bleeding into each other across the boundary line.
• Correctable: If you paint the wrong colour into a section, you simply wait for it to dry and paint the correct colour over the top. The opaque coverage means the error disappears completely in a single coat.

Acrylic paint covers the printed numbers and dividing lines completely in a single coat. This is the defining requirement of any paint by numbers kit and the reason acrylic is always the correct choice.

Why Watercolour Does Not Work on a Paint by Numbers Canvas

Watercolour paint contains pigment suspended in gum arabic, a natural water-soluble binder. The result is a translucent medium that allows the surface beneath it to show through. This is watercolour's defining quality and the reason it produces such beautiful, luminous artwork on the right surface. It is also precisely why it fails on a paint by numbers canvas.

• No opacity: Watercolour is translucent by nature. Apply it over a numbered section, and the printed numbers, outlines, and canvas texture all show through. The finished painting looks like a washed-over diagram rather than a finished artwork.
• Wrong surface: Watercolour is designed for absorbent watercolour paper, which allows the pigment to spread and settle in a controlled way. Linen canvas, which is what paint by numbers kits use, does not absorb watercolour correctly. The paint beads spread unpredictably and produces muddy results.
• Cannot correct mistakes: Watercolour pigment soaks into the surface and cannot be painted over. A mistake in watercolour means repainting the entire section from scratch, which is extremely difficult to do cleanly on a pre-printed canvas.

Key Differences Between Acrylic and Watercolour

Beyond the specific question of paint by numbers, here is how the two mediums compare across the properties that matter most to painters.

Is Watercolour Ever Better Than Acrylic?

Yes, in specific contexts. Watercolour produces a uniquely luminous, soft quality that acrylic cannot replicate. When you thin acrylic with water to create a wash, you get something close, but it is not the same. The light that passes through watercolour pigment and reflects back off white paper has a quality that experienced watercolour artists specifically seek out.

Watercolour is also more portable. Dried pans of watercolour paint can be reactivated with a wet brush anywhere, which makes it popular for sketching outdoors. Acrylic requires keeping pots sealed and working within the drying time.

But these advantages are entirely irrelevant to paint by numbers. For a guided, numbered canvas, acrylic wins on every dimension that matters: coverage, speed, correctability, and durability. If you want to explore watercolour as a standalone painting medium after building your skills through paint by numbers, that is a natural progression. But the two hobbies have different tools, different surfaces, and different techniques.

What Paint Do Paint by Numbers Kits Use?

Every Paint on Numbers kit uses high-pigment acrylic paint, pre-mixed and numbered to match every section of your canvas exactly. You never need to mix colours yourself. Each pot corresponds to a number on the canvas, and the paint is formulated to provide full opacity in a single coat on our premium linen canvas.

The paint is water-based, non-toxic, and ASTM D-4236 compliant, which means it meets the safety standards required for art materials used indoors. Clean-up is straightforward with water, provided you rinse your brush before the paint dries on the bristles. For guidance on the right painting sequence, read our painting order guide, which covers brush technique and session management, too.

Every Paint on Numbers kit includes a full set of pre-mixed, numbered acrylic paints matched precisely to your canvas. No mixing, no guesswork, and full opacity in a single coat.

Acrylic as a Gateway to Other Mediums

One of the most valuable things about learning to paint through a paint by numbers kit is that acrylic teaches you the fundamental skills that transfer directly to every other painting medium. Colour recognition, brush control, working light to dark, and understanding how paint behaves as it dries are all skills you build naturally through acrylic.

Many painters who start with beginner kits and progress through to more complex designs eventually become curious about freehand painting. Acrylic is the natural next step: the same paint, the same brushes, and the same canvas, but without the numbered guide. From there, the transition to watercolour or oil is a deliberate choice based on the kind of finished result you want, not a necessity.

Paint by numbers is not just a craft kit. It is the most structured, least intimidating way to start painting, and the acrylic skills you build through it are the same ones that artists use every day. Start with a kit, build confidence, and the rest follows naturally. For the full picture on how the hobby benefits you beyond the canvas, read our paint by numbers for mental health and wellbeing guide.

Further Reading

Now that you understand your paints, the natural next questions are about technique and timing. Our guide on whether to paint light or dark colours first covers the correct painting order that makes acrylic work best. For help planning your sessions, read our guide on how long paint by numbers takes. And when you are ready to choose your next kit, our best paint by numbers kits UK 2026 guide covers our full ranked picks.

Frequently Asked Questions

Is watercolour or acrylic better for paint by numbers?
Acrylic is better for paint by numbers in every meaningful respect. It is opaque enough to cover the printed numbers and canvas lines, dries fast enough to work on adjacent sections in the same session, and corrects easily by painting over dried mistakes. Watercolour is translucent and leaves the printed outlines visible through the paint, producing an unfinished result.

Why do paint by numbers kits use acrylic paint?
Because acrylic is opaque, fast-drying, and correctable. These three properties are essential for a numbered canvas. Acrylic covers the printed guide lines completely, dries in minutes so adjacent sections do not bleed into each other, and allows mistakes to be painted over cleanly once dry.

Can you use watercolour paint for paint by numbers?
Technically, yes, but the results are significantly worse. Watercolour is translucent and will not cover the printed numbers and outlines on a paint by numbers canvas. The finished painting will look washed out rather than bold and vibrant. Watercolour also requires watercolour paper to behave correctly, not the linen canvas that kits use. Acrylic is always the right choice.

Is acrylic or watercolour easier for beginners?
Acrylic is significantly easier. Mistakes can be corrected simply by waiting for the paint to dry and painting over it. Watercolour mistakes are very difficult to reverse because the translucent pigment soaks into the paper. Acrylic also dries quickly and produces consistent, opaque coverage that beginners find far more forgiving.

What is the difference between watercolour and acrylic paint?
The key difference is opacity. Acrylic is opaque and sits on top of the surface, covering what is beneath it. Watercolour is translucent and allows the surface and underlying layers to show through. Acrylic dries permanently and cannot be reactivated. Watercolour can be reactivated with water even after drying. Acrylic works on most surfaces including canvas, while watercolour requires absorbent paper.

How long does delivery take?
Allow 2 to 3 business days for processing, then 6 to 8 business days for delivery across the UK.

About the Author: William Murdock

Founder of Paint on Numbers UK. William has guided thousands of UK painters through their first kit and believes that understanding your materials is what turns a good painting session into a great one.