Best Stain Block Paint

The best stain block allows you to cover tough stains without the fear of them re-surfacing and bleeding through the paint.

Water stains, crayons, nicotine and grease can prove to be problematic if not treated correctly. The stains will continue to grin through standard emulsions and primers. Stain blocking allows a specialist highly pigmented coating to seal the stain before painting over.

The reviews are based on hands on use by experienced applicators.

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The No. 1 Stain Block Paint 2021

The top spot of the stain block paints was Zinsser Cover Stain

A solvent based stain block that not only covers stains internally but externally as well.

Stain Block Comparison

Stain BlockerCoverage m2 per LSize
Zinsser Cover Stain9.81L
Polycell One Coat Stain StopNot Stated1L
Rustins Stain Blocker9-10250ml
Thompson’s Stain Block Damp Seal5750ml
Johnstone’s Paint to Block Stains9.3750ml

The Best Stain Block Paints

1. Zinsser Cover Stain

Cover Stain by Zinsser is an ideal way of combating unsightly stains before painting.

Stains of all kinds are sealed to hide them before painting with your top coats. Effective on water and nicotine stains.

The paint resists cracking and peeling even on exterior surfaces and is compatible with majority of top coats.

It is a thick coating that covers extremely well and acts as a primer. We used the brilliant white which was great at covering. It then only required one coat of emulsion over the top.

This paint is also suitable for priming dark stained wood to provide an excellent base coat. It is oil-based and has unparalleled adhesion to glossy surfaces.

The main features of Zinnser Cover Stain:

  • For interior and exterior
  • All in one Primer, sealer and stain killer
  • Dries quickly, normally in 30 minutes
  • Can re-coat in 2 hours
  • Amazing hiding power

To combat water and nicotine stains before painting this is an excellent choice of stain block paint .

2. Polycell One Coat Stain Stop

Polycell One Coat Stain Stop is a specialist paint that helps to prevent existing stains from grinning through freshly coated paint.

It is highly pigmented meaning that it will hide the toughest of stains including water statins, grease, nicotine, crayons, rust and soot.

Features of Polycell One Coat Stain Stop:

  • Highly pigmented paint
  • Compatible with emulsion paints
  • Permanently prevents existing stains from appearing
  • One Coat Coverage
  • Suitable for most stain

As a sealer primer, it is a very thick pigmented coating perfect for hiding a multitude of stains. This stain block is also available in an aerosol form.

It can be applied by brush or roller.

A good choice of stain block for use on plaster, masonry, plasterboard and wood.

3. Rustins Stain Blocker

Rustins produce an all in one stain block and primer.

The paint is a water based white matt finish sealer primer that drys quickly.

The primer can be used with the majority of topcoats and undercoats and has excellent adhesion to plaster, wood and painted surfaces. It can also provide excellent adhesion to ceramic tiles, glass, and melamine.

The features of Rustins Quick Dry Stain Block and Surface Primer:

  • Seals stubborn stains that bleed through.
  • For indoor and outdoor use
  • For DIY and Trade uses.
  • Highly effective against a range of stains.
  • Use as a primer with any top coat paint emulsion

It can be used on interior and exterior surfaces and seals most stains that bleed through including crayon, water stains, tannin, rust, nicotine, graffiti, creosote and bitumen.

An ideal stain block for the trade or DIY projects.

4. Thompson’s Stain Block Damp Seal

Thompson’s produce a sealer that acts as a damp block and stain block in one.

The coating is a high performance seal that allows the surface to breathe and lets moisture escape whilst also sealing the stain beneath. This formulation allows trapperd damp to escape and prevent any falking or peeling paint.

It can be applied in just one or two coats using a brush.

A very thick coating that offers a high level of protection.

Main features of Thompson’s Stain Block:

  • Can be applied directly over damp surfaces
  • Ready to overcoat in 4 hours
  • Can be applied to all types of stain
  • Stops appearance of stains
  • Micro-porous formulation allows moisture to escape

For use on interior walls and ceiling that are affected by damp stains this product is ideal for blocking stains whilst allowing moisture to escape.

5. Johnstone’s Paint to Block Stains

Johnstone’s have developed a coating and called it a completely unoriginal name but describes exactly what the coating was designed for- Paint to Block Stains.

It is effective at covering a range of difficult stains such as tannin and bitumen, graffiti, wax crayons, marker pens, nicotine and water damage.

It may take a few coats, 2-3 to get the desired effect.

Main features of Johnstone’s Paint to Block Stains:

  • Matt coating finish
  • Excellent covering
  • Covers and protects against stains grinning through
  • Tough and durable primer
  • Block aginst all types of tough stain

Overall this stain block paint protects against stain from showing through.


If you have ever experienced a leak onto a ceiling in your house you will know how annoying it is to paint over. The best solution, in the long run, is to spot prime with a stain block that seals and provides a suitable surface to paint upon.

Stain blocking paints are available in both wet paint and aerosol form for convenience. If you a stain it is well worth investing and spending time treating the stain to prevent it from showing through.

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