Paint flashing, often described as uneven shine or inconsistent sheen, is a common issue that becomes noticeable once a painted wall begins to dry. It shows up as shiny patches, dull spots, or streaks that look different from the rest of the surface. Flashing usually happens when the wall absorbs paint unevenly or when surfaces have not been prepared correctly. Here is what causes it and how to prevent it from happening in your home.
What is paint flashing?
Paint flashing occurs when light reflects differently across the wall because of inconsistent surface texture or absorption. It is especially visible on smooth walls or in rooms with natural sunlight. Flashing can make even a fresh paint job look uneven.
What causes paint flashing on interior walls?
Flashing typically happens for several reasons:
Uneven surface porosity
Walls absorb paint at different rates if they contain unprimed patches, drywall mud, or sanded areas.
Unprimed repairs
When holes, cracks, or filler patches are painted without a primer, they dry with a different sheen.
Painting over glossy finishes
Glossy surfaces repel paint. Without proper sanding or priming, they cause uneven drying.
Incorrect paint application
Rolling too lightly, pressing too hard, or overlapping partially dried areas can create shine variations.
Low quality tools
Worn or cheap rollers and brushes often leave thin sections of paint that dry differently.
Does lighting make flashing more noticeable?
Yes. Flashing becomes much more apparent in bright or angled light. Rooms with natural sunlight, LED spotlights, or strong overhead lighting will highlight sheen inconsistencies on walls.
Painting in good light helps you see coverage clearly and prevents missed spots.
How can you prevent paint flashing?
You can avoid flashing by following good preparation and application practices:
- Prime all repaired or bare areas
- Use a full primer coat before painting over patches
- Apply two even coats of paint, not one heavy coat
- Use high quality brushes and rollers
- Maintain a wet edge while painting to prevent lap marks
- Ensure walls are dust free and smooth before painting
- Paint in bright, even lighting
Premium primers and paints available in the Randall’s Collection provide reliable, consistent sheen and make flashing less likely.
https://randalls.ca/collection
How do you fix paint flashing once it appears?
Flashing cannot be fixed with a simple touch up because the sheen difference will remain. To correct the issue:
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Lightly sand the affected area
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Prime the entire wall or the entire section
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Repaint with two even coats
A full wall repaint is usually required for a perfectly even finish.
Are some finishes more prone to flashing?
Yes. Flat and matte finishes show flashing most easily because they absorb paint quickly and highlight surface imperfections.
Satin, semi gloss, and gloss finishes can also flash, but the issue usually appears as streaks or uneven gloss levels.
Proper priming reduces the risk across all finishes.
Can temperature or humidity cause uneven shine?
Yes. Paint that dries too fast or too slowly will not level properly. This can create patches that reflect light differently.
Ideal indoor conditions for painting:
- Temperature between 10 and 25 degrees Celsius
- Humidity between 40 percent and 60 percent
Balanced airflow helps paint dry consistently.
When should you hire a professional painter?
If your walls have many repaired areas, multiple sheen inconsistencies, or a difficult texture, a professional painter can help achieve an even finish. Professionals understand how to prepare surfaces correctly and prevent flashing.
You can connect with trusted local painters through the Randall’s Services page:
https://randalls.ca/pages/services
Or submit a request using the Paint Order Form:
https://randalls.ca/pages/painter-order-form
Where can you get expert help choosing the right paint and primer?
Randall’s paint specialists can help you choose the best products, tools, and primers to prevent flashing and achieve a smooth, consistent finish. Visit a local store or reach out through Contact us:
https://randalls.ca/pages/contact-us
Explore high performance primers, paints, and supplies in the Randall’s Collection:
https://randalls.ca/collection
Consistent sheen begins with proper preparation and quality materials. Randall’s provides the expert advice and premium products you need for flawless results.