Table of Contents

• Why Paint by Numbers Mistakes Happen
• Mistake 1: Painting With Too Much Paint on the Brush
• Mistake 2: Painting the Wrong Color in a Section
• Mistake 3: Letting Paint Dry Out in the Pots
• Mistake 4: Ignoring Canvas Creases and Wrinkles
• Mistake 5: Using the Wrong Brush Size
• Mistake 6: Painting in Random Order
• Mistake 7: Not Rinsing Brushes Properly Between Colors
• Mistake 8: Painting Under Poor Lighting
• Mistake 9: Rushing to Finish Quickly
• Mistake 10: Skipping the Varnish Coat
• Bonus Mistakes: Three More Traps That Catch Intermediate Painters
• Prevention Checklist: Set Yourself Up Before You Start
• Frequently Asked Questions

Common paint by numbers mistakes cost you time, waste paint, and sometimes ruin an entire canvas. The frustrating part is that almost every single one of them is preventable with a few minutes of preparation. This guide documents the 10 most frequent problems people encounter with their paint by numbers kit, explains exactly why each one happens, and gives you a concrete fix. If you are working on your first numbered canvas painting — or your tenth — this list will save you from the errors that turn a relaxing creative hobby into a headache.

Why Paint by Numbers Mistakes Happen

Most paint by numbers mistakes share the same root cause: impatience. The excitement of a new kit makes people skip preparation steps, rush through sections, and ignore small problems that compound over time. The other major cause is lack of information — nobody explained the proper technique, so people default to guessing.

The good news is that acrylic paint is one of the most forgiving mediums. Nearly every mistake in this guide can be fixed without starting over. Acrylic dries fast, layers well, and covers previous colors with minimal effort. The key is catching problems early and knowing the right correction technique.

Mistake 1: Painting With Too Much Paint on the Brush

What happens: You dip your brush deep into the pot and slather paint onto the canvas. The result is a thick, uneven layer with visible brush marks, raised ridges, and sections where paint pools in the corners. As the thick layer dries, it can crack, peel, or obscure the fine details that make the finished painting look impressive.

Why it happens: Beginners assume more paint equals better coverage. It feels efficient to load up the brush and cover a large area in one stroke. But acrylic paint on a numbered canvas works differently than house paint on a wall.

The fix: Dip only the bottom third of the brush bristles into the paint. Before touching the canvas, wipe one side of the brush against the rim of the pot to remove excess. Apply paint in thin, even strokes. If coverage looks patchy after the first coat, let it dry for 5 to 10 minutes and apply a second thin coat. Two thin layers always look better than one thick one — this is the single most important technique in paint by numbers.

Pro tip: Hold your brush perpendicular to the canvas for filling sections, and at a 45-degree angle for edges. The perpendicular angle distributes paint more evenly, while the angled grip gives you precision control near section borders.

Mistake 2: Painting the Wrong Color in a Section

What happens: You finish painting 15 sections with color 6, then realize you have been using color 9 the entire time. The painting looks wrong, and panic sets in.

Why it happens: Small printed numbers on canvas are easy to misread. "6" and "9" are the most commonly confused pair, followed by "1" and "7," and "3" and "8" in certain fonts. Poor lighting makes this even worse. Some people also confuse the paint pot labels, especially when pots are not organized in order.

The fix: Let the wrong color dry completely — do not try to fix it while wet, or you will create a muddy mess. Once dry, paint over the incorrect sections with the correct color. Acrylic paint is opaque enough that one or two coats of the right color will cover the mistake entirely. For a dark error under a light correction (like dark blue painted where pale yellow should be), you may need three thin coats.

Prevention: Always verify the number on the canvas against the number on the pot before painting. Use a magnifying glass for tiny numbers. Some painters circle or highlight each number on the canvas with a colored pencil before painting, which makes identification faster.

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Mistake 3: Letting Paint Dry Out in the Pots

What happens: You open several paint pots at the beginning of a session, forget to close them, and come back the next day to find the paint has turned into a solid, unusable lump. This is the number one complaint among paint by numbers beginners, and it is entirely preventable.

Why it happens: Acrylic paint is water-based and dries through evaporation. Once the pot is open, the clock starts ticking. In a warm, dry room, exposed acrylic paint can skin over in 15 to 30 minutes and harden completely overnight.

The fix: If the paint is only slightly thickened (still soft when you press it), add 2 to 3 drops of water, stir thoroughly with a toothpick, and let it sit for 10 minutes before testing. If it has formed a skin on top but is still liquid underneath, peel off the skin and use the remaining paint. If the entire pot has solidified, the paint is gone — you will need a replacement pot or a matching color from a craft store.

Prevention: Only open one paint pot at a time. Close it immediately after loading your brush. Develop the habit of reaching for the lid as a reflex every time you lift the brush from the pot. Some painters wrap a small piece of plastic wrap under the lid for an extra seal.

Mistake 4: Ignoring Canvas Creases and Wrinkles

What happens: The canvas arrives with fold marks or rolling creases from packaging. You ignore them and start painting. Paint pools in the creases, dries unevenly, and the finished painting has visible lines running through it that no amount of varnish will hide.

Why it happens: Excitement. The kit arrives, you want to start immediately, and flattening the canvas feels like an unnecessary delay.

The fix for existing creases: If you have already painted over creases, the damage is mostly cosmetic. Heavy varnishing can reduce their visibility slightly, but it will not eliminate them. For unpainted creases, iron the back of the canvas on the lowest heat setting with no steam, or place it under a stack of heavy books for 24 hours.

Prevention: Always flatten your canvas before painting. This takes 5 minutes with an iron or overnight with books. It is the easiest step in the entire process and makes the biggest difference in the final result.

Mistake 5: Using the Wrong Brush Size

What happens: You use the large flat brush for tiny detail sections, resulting in paint splashing into neighboring areas. Or you use the fine detail brush for a large sky section, taking 20 minutes to cover what should take 3 minutes.

Why it happens: Beginners often find one brush they feel comfortable with and use it for everything. The large brush feels unwieldy for some, so they default to the medium. The fine brush feels precise, so they use it everywhere.

The fix: Match the brush to the section size. Use the large flat brush for any section bigger than a postage stamp. Use the medium round brush for medium sections and edge work. Use the fine detail brush only for the smallest sections — individual leaves, eyes, thin lines, and tiny decorative elements. Switching brushes frequently feels slower at first but produces much better results and actually saves time overall.

For intricate sections: A detailed animal portrait has many more tiny sections than a landscape. If you have chosen a complex kit, you will use the fine brush more often. Make sure you are comfortable with it before starting.

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Mistake 6: Painting in Random Order

What happens: You paint whatever catches your eye — a bit of sky here, some foreground there, a random detail in the corner. The result is an uneven-looking painting where different areas have different coverage quality, and you constantly struggle with wet paint touching dry sections at awkward angles.

Why it happens: Without a strategy, the canvas feels overwhelming. Random painting feels like progress because you can see bits of color appearing everywhere. But scattered work means more brush cleaning, more pot opening and closing, and more chances for color contamination.

The fix: Follow this order for the best results:

1. Paint one color at a time. Open a pot, find every section on the canvas with that number, and complete them all before moving on. This is the most efficient approach.
2. Start with dark colors, finish with light colors. Dark paints cover numbers better and provide a strong base. Light colors applied last stay clean and vibrant.
3. Work top to bottom. This prevents your hand from resting on freshly painted areas.
4. Complete the background before the foreground. Backgrounds are usually larger and simpler. Getting them done first creates a satisfying base and makes the painting feel more complete, motivating you to continue.

Mistake 7: Not Rinsing Brushes Properly Between Colors

What happens: You switch from dark blue to pale yellow, give the brush a quick swirl in water, and start painting. The yellow comes out greenish because blue pigment is still in the brush. Multiple sections now have a muddy, contaminated color instead of the clean yellow they should be.

Why it happens: Thorough rinsing feels tedious. A quick dip seems like enough. But acrylic pigments cling to brush bristles, especially in the ferrule (the metal part where bristles meet the handle). A single swirl in water dislodges surface paint but leaves pigment trapped deeper in the bristles.

The fix: Rinse your brush in clean water, pressing the bristles against the bottom of the cup to splay them and release trapped pigment. Repeat until the water running off the brush is completely clear. Then dab the brush on a paper towel to remove excess water before dipping into the new color. If you are switching from a very dark color to a very light one, use two cups of water — rinse in the first (dirty) cup, then rinse again in the second (clean) cup.

Change your water regularly. When the water cup turns dark and opaque, it is no longer cleaning your brush — it is contaminating it. Swap for fresh water every 15 to 20 minutes during active painting.

Mistake 8: Painting Under Poor Lighting

What happens: Colors look accurate while you paint but appear completely different in daylight. You realize that what you thought was a warm beige was actually a dusty pink, or the dark green you applied was actually dark teal. The painting looks off, and you cannot figure out why until you see it in proper light.

Why it happens: Warm-toned incandescent bulbs shift all colors toward yellow. Cool fluorescent tubes add a blue cast. Dim lighting makes similar shades indistinguishable. Your brain adapts to the available light, so you do not notice the distortion while painting.

The fix: Paint under a bright, neutral-white light source. A daylight LED bulb (5000K to 6500K color temperature) is ideal. Position the light source above and slightly to the side to avoid shadows from your painting hand. If you have been painting under poor light and notice color discrepancies, check each section against the reference image under daylight conditions and repaint any sections that are clearly wrong.

Mistake 9: Rushing to Finish Quickly

What happens: You try to complete the painting in one or two marathon sessions. Your hand cramps, your focus deteriorates, and the quality of your brushwork declines dramatically in the second half of the painting. Sections you painted while tired look noticeably worse than sections you painted when fresh.

Why it happens: Impatience and excitement. You want to see the finished result. But paint by numbers is designed as a long-term project — a stress relief painting activity meant to be enjoyed over days or weeks, not blasted through in one sitting.

The fix: Paint in sessions of 1 to 3 hours. Take breaks every 45 minutes to stretch, rest your eyes, and let recently painted sections dry. Most kits take 10 to 25 hours total. Spread that over two to three weeks and enjoy the process rather than racing toward the finish line. You will produce better work and actually enjoy the creative hobby instead of treating it like a chore.

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Mistake 10: Skipping the Varnish Coat

What happens: You finish the painting, hang it on the wall, and within a few months the colors look dull, dust has embedded itself in the paint surface, and the painting looks faded compared to when you finished it.

Why it happens: Varnishing feels like an extra unnecessary step after hours of painting. The painting looks great when you finish it, so why add another layer?

The fix: Apply two thin coats of clear acrylic varnish. Choose matte for a subtle, modern look, satin for a balanced finish, or gloss for vibrant, deep colors. Use a clean, wide, soft brush. Apply in long, even strokes in one direction. Let the first coat dry completely (4 to 6 hours) before applying the second. Varnish protects against UV damage, dust, moisture, and physical contact. It also evens out the sheen across the painting — areas that dried shinier or more matte become uniform.

Spray varnish alternative: If brushing varnish feels risky, spray-on acrylic varnish works well and eliminates brush stroke marks. Hold the can 12 inches from the canvas and apply in light, even passes. Two to three light coats are better than one heavy coat, which can cause drips.

Bonus Mistakes: Three More Traps That Catch Intermediate Painters

Once you have completed two or three kits and feel comfortable with the basics, a new set of mistakes emerges.

Over-blending at section borders: Some intermediate painters try to blend colors at the borders between sections, thinking it will make transitions smoother. On a paint by numbers canvas, this usually backfires. The sections are designed to create the illusion of blending through color placement — the same way pointillist paintings create smooth images from individual dots. Trust the design.

Choosing overly complex kits too soon: After finishing a beginner kit, jumping to an advanced kit with 40+ colors and hundreds of tiny sections is tempting. The leap in difficulty is often much larger than expected. Progress through medium-complexity kits first. Abstract designs make excellent intermediate projects because they have complex color patterns but forgiving composition — a slightly off stroke still looks intentional.

Not protecting the finished painting: Even with varnish, hanging a painting in direct sunlight, above a radiator, or in a humid bathroom accelerates degradation. Choose a wall location that avoids extreme conditions.

Prevention Checklist: Set Yourself Up Before You Start

Run through this list before opening your first paint pot on any new kit:

• Canvas flattened — no creases or wrinkles
• Workspace covered with protective material
• Bright, neutral-white light positioned correctly
• Paint pots organized in numerical order
• All three brush sizes clean and ready
• Cup of clean water and paper towels within reach
• Reference image printed or displayed on a screen nearby
• Magnifying glass available for tiny numbers
• Varnish purchased and ready for when you finish
• Comfortable seating with back support

This 10-item checklist takes 5 minutes to complete and prevents 90% of the mistakes in this guide. Print it out and tape it to your painting area.

Every ArtistryByNumbers kit ships with everything you need to get started — premium acrylic paint set, numbered linen canvas, three brushes, and a full-color reference image. Starting at just $19.95 with free worldwide shipping and our popular Buy 2 Get 1 Free offer.

Frequently Asked Questions

Can I fix a paint by numbers painting after it dries?

Acrylic paint is fully opaque, which means you can paint over dried sections with a new color at any time. Let the mistake dry completely, then apply one or two thin coats of the correct color. For dark-over-light corrections, a single coat usually suffices. For light-over-dark corrections, you may need two to three coats.

My paint is too thick. Can I thin it?

Add one or two drops of clean water to the pot and stir with a toothpick. The consistency should be like heavy cream — smooth enough to flow off the brush but thick enough to cover the canvas in one pass. Do not add too much water or the paint becomes translucent.

How do I stop numbers from showing through light colors?

Apply a thin base coat of white paint first. Let it dry, then apply the light color on top. This blocks the printed numbers and makes colors like yellow, pale pink, and light blue appear much more vibrant.

What if I lose a paint pot or it spills?

Contact the kit manufacturer for a replacement. ArtistryByNumbers provides replacement pots at no additional cost. Alternatively, bring the reference image and a remaining pot to a craft store — staff can help you match the exact shade in a standard acrylic tube.

Is it normal for my painting to look messy before it is finished?

Completely normal. Every paint by numbers canvas looks like a confusing patchwork until about 70% completion. The magic happens in the final 30%, when colors come together and the image clicks into place. Do not judge your progress until you are at least three-quarters done.

How many kits should I complete before trying an advanced design?

Complete two to three beginner or intermediate kits first. This gives you enough brush control and technique confidence to handle the tiny sections and complex color gradients in advanced kits. Check our best sellers for popular progression options.