When dirt or dust gets into a tin of paint, you have a problem. The same is true when you use paint from a previously opened can. Dried flakes of old paint from the sides of the can often find their way into the mix. If you do not get every last little bit of this debris out, you will end up with unsightly blemishes in any paint job you attempt. Strain the paint to solve the problem.
Cut one leg from a pair of old pantyhose, using scissors. Check that the pantyhose material has no holes or ladders in it.
Stretch the piece of pantyhose over the top of a bucket. Tape the edges of the pantyhose material around the rim of the bucket, using masking tape.
Push the centre of the nylon pantyhose material down until it forms a loose bag inside the bucket.
Put several small pebbles in the bottom of the nylon bag you have made, if it refuses to stay open. Use smooth, rounded pebbles rather than rough stones to avoid tearing the nylon bag.
Pour the paint out of its can and into the nylon bag. The paint will seep through the nylon mesh and into the bucket, becoming clean and ready to use. Any debris will be caught by the mesh and remain inside the bag.
Scrape any paint remaining inside the can into the bag, using an old kitchen knife. Scrape any paint from the can's lid too. This process will leave the can clean and empty, which allows you to store your paint back in it after it has been strained.
Remove the masking tape and lift up the nylon bag when most of the paint has seeped out of it. Hold the bag over the bucket with one hand and squeeze the nylon firmly with the other hand to get the last of the paint out. Wear rubber gloves for this process, especially if the paint is not water-based and easy to wash away.
Dispose of the nylon bag unless the pair is water-based. If the paint is water-based, wash the bag out, dry it and store it until you need to reuse it.
Pour the paint out of the bucket and back into the can. Replace the lid on the can to keep the paint in good condition until you need to use it.
Use a bucket big enough to contain all the paint from the can. Straining a large can of paint into a small bucket means you will have to do it in several batches, which can be messy and inconvenient. If you do not have any old pantyhose, purchase a mesh bag for straining paint from a home improvement store. You can strain varnish through a nylon mesh in the same way as paint.