If you run into uneven or blotchy paint, the best thing to do is start over. The first crucial step in getting back on track is to prime the area you're painting. Once your primer is dry, begin painting—this time knowing that you've primed your surface and set your project up for success.
Just do a light sand so that the paint is level but not removed and apply again. Depending on the paint brand it can need several layers to reach full opacity, especially with white.
Sand the wall lightly to smooth out any imperfections. Prime the wall with a good quality primer before painting. This will help to seal the surface and prevent the paint from soaking into the drywall, which can cause the paint to appear uneven.
Painting over existing layers of paint is usually the easiest option. A paint that has high coverage and a thick texture, such as our Claypaint or Lifestyle emulsions, will even out any hairline cracks and slightly bumpy surfaces. Both products can go over a multitude of wall substrates.
Wall condition: If your walls are in good condition, you may only need one or two coats of paint to achieve a smooth, even finish. However, if your walls are rough or damaged, you may need to apply additional coats to cover up imperfections.
Patchy paint can result if paint has been applied unevenly. Patchy paint can be down to a variation in surface absorption. Walls might appear patchy if they have variation in texture. Using paint that is not fully mixed can cause a patchy appearance.
Brush marks are caused by strokes that leave the paint with a rough texture and visible brush strokes. The rough texture and visible brush strokes can be easily covered in a second coat of paint by using a slightly different technique than you used for your first coat.
More neutral colors are another choice for hiding imperfections. Stray away from lighter shades, as they can highlight the blemishes. Mid-tone neutrals like: Gray.
Of the two, satin is more durable and is slightly less likely to scuff or mark than eggshell and it's easier to clean when it does get marked. This makes it a better choice, especially for woodwork such as painting skirting boards, than eggshell for high traffic areas like hallways and living rooms.
Without primer, the touched-up spot will stand out, and it'll look a right mess. The trick is to blend the new paint with the original surface. Priming will also prep your surface for paint and seal any stains - especially those that wouldn't come off.
If the humidity is too high, the solvents in the paint will take longer to evaporate. This long drying time cause the paint to dry with a darker appearance, though it can also lead to uneven drying, streaks, and paint discoloration.
Dilute the paint by 5 to 10 percent with water for latex-based paint or mineral spirits for oil-based paint. Stored paints can lose moisture, making it more difficult for touch-ups to match the original coat.
Unfortunately, roller marks will probably not go away when the paint dries out. However, as the paint dries some of the roller marks will become slightly less noticeable. But simply waiting until the paint has dried won't solve the problem completely.
Reapply another coat to fill in bare spots. If there are clumps or bubbles on the painted surface, sand it, wipe clean, and reapply a coat of paint. To avoid streaks or lap marks from a roller, maintain a wet edge by applying paint toward the unpainted area and then back into the just painted area.
These can occur when the paint roller isn't fully immersed in the paint or is applied unevenly, leaving a patchy, streaky appearance once the paint has dried. Second, brush marks are another common cause of streaks.
Ceilings and Drywall - Medium 3/8″ roller covers work best. Walls, Wood, and Metal - Small 1/4″ roller covers or foam rollers will produce the smoothest finish. Light to Medium Textured Surfaces - Microfiber rollers are best. Smooth Surfaces - Use a white woven short nap roller for an ultra fine finish.
Color Considerations
We all know that lighter colors emphasize imperfections while darker colors hide them. This also has to do with light and reflection. Lighter colors reflect more light while darker shades absorb it.
The main problem is that wicking will not occur at the same rate on a touch-up job versus the wicking rate of the original top coat. It is virtually impossible to reproduce the exact wicking rate, and this is why a touch-up job will often appear as a slightly different color than the original paint.