Why should I use a primer if I'm painting over existing paint?

Using primer over old paint might seem like extra work, but it can actually make painting easier and look better in the end. Primer helps seal the previous paint, preventing the new paint from bleeding through and creating an uneven finish. It also provides a consistent surface for the new paint to adhere to, ensuring smooth coverage and preventing uneven color patches.

Can I apply primer with a roller?

<a href="https://www.homedepot.com/b/Paint-Primers/Roller/N-5yc1vZbt0tZ1z0ky1u?emt=plpfaq_2408_primers" style="text-decoration: underline;">Rollers</a> are an excellent option for applying primer, especially for large surfaces like walls and ceilings. Choose a roller with a nap appropriate for the surface you're working with, and remember to use a smooth and even rolling motion for optimal coverage.

What is the difference between a flat and a semi-gloss primer?

The sheen of a primer refers to its level of reflectivity. A <a href="https://www.homedepot.com/b/Paint-Primers/Flat/N-5yc1vZbt0tZ1z1vuja?emt=plpfaq_2408_primers" style="text-decoration: underline;">flat primer</a> has a matte finish, offering a subtle, non-reflective look. This is a good choice for walls and ceilings, as it can help to hide minor imperfections. On the other hand, a <a href="https://www.homedepot.com/b/Paint-Primers/Semi-Gloss/N-5yc1vZbt0tZ1z10m17?emt=plpfaq_2408_primers" style="text-decoration: underline;">semi-gloss primer</a> has a more reflective finish, which can help highlight the surface and make it more durable. This is a good choice for areas with high traffic or needing easy cleaning, like trim or doors.