Why, When & How to Use Primer

ECOS 03/05/2024

Some people say it’s always best to prime before you paint and others say the exact opposite, that it’s actually unnecessary to prime at all. Who’s right? Both – it totally depends on the project. Oftentimes, priming will give you the best results and most beautiful finish, so it’s not a step that should be universally skipped. Other times, you can completely forget about it. Today we’re sharing which is which. Here’s why, when & how to use primer.


Primer seals the surface and helps create a bond so that the paint adheres better. This creates a more professional looking finish and also makes it last longer. Primer also blocks colors – a must if you’re painting a light color over a dark one.


  • New Drywall - Primer is an absolute must on new sheetrock (Drywall and Plasterboard) and mudded (joint compounded) surfaces. The new drywall and sanded mud will soak up a lot of paint at first, so the primer works to seal the drywall and create a uniform surface on which to apply the paint. One coat of ECOS Interior Wall Primer will be sufficient.
  • Bare Wood - Bare wood soaks up even more paint than drywall does, so you definitely need to prime it. ECOS Interior Wood Primer is perfect for all types of wood including plywood and fiberboard.
  • Stained Surfaces - Primers like ECOS Paints Universal Primer block stains from water damage, knots in wood, and rusted metal. If you try to paint over these stains without using a special primer, the stains will bleed through the paint even after multiple coats.
  • Seal in VOCsECOS Paints Interior MDF Passivating Primer is a unique primer that can be used on new particleboard, plywood, and other manufactured wood products. If you’re chemically sensitive, this primer absorbs formaldehyde and other VOCs down to approximately 1 ppm.
  • Painting Over Dark Colors - As with stains, dark colors can bleed through lighter ones, so using a white primer will create the best base coat for your new color.


If the surface has already been painted, is in good shape, free of patches, without stains, and a fairly light color – then you can skip the primer and go straight to paint. Wipe down the surface first with a Washing Soda and water solution to remove dust and that should be all the prep work you need to do.


All primers are applied using a brush or roller – the same as paint. They can also be used in an airless sprayer. One coat is usually sufficient, but in the case of stains, you may need two if they’re bleeding through. After the primer coat is dry, you’re ready for your paint.

Still have questions about primer? Let us know in the comments – we’re happy to help!

CATEGORIES Tips & Tricks