Absolutely! Paint strainers will remove impurities and lumps from your paint, resulting in a smoother, more even finish. They are especially useful for latex and water-based paints, as well as paints that have been sitting for a while and may have developed some settling.

The mesh size of your paint strainer will depend on the type of paint you're using and the desired finish. For most general-purpose applications, a 190-micron strainer is a good choice. For finer finishes, such as those required for automotive or marine applications, a 125-micron or even 90-micron strainer may be necessary.

Paint can thicken over time due to a number of factors, including evaporation of solvents, absorption of moisture, and chemical reactions between the paint components. Thicker paint can be more difficult to apply and may result in a less-than-ideal finish. Using a paint strainer can help to remove any thickened paint particles, ensuring a smooth, even application.

Whether or not you can reuse a paint strainer depends on the type of paint you're using and the condition of the strainer after use. For water-based paints, you can usually reuse a strainer a few times by simply rinsing it out with water. For oil-based paints, it's best to dispose of the strainer after a single use.