Free UK mainland delivery on orders over £50*

Johnstone's Trade Primer & Undercoat

Ask anyone in the trade what the difference between a paint job done well and a paint job done right is, and somewhere in the discussion, they should mention primer & undercoats. It's easy to underestimate how important using these is to helping any paint project look as you wish.

Luckily, you don't have to look too far for a reliable primer or undercoat as The Paint Shed has a fantastic range of Johnstone's Trade Prime & Undercount in stock, at unbeatable prices.

Before you even think of letting a lick of paint touch a wall, get yourself some primer or undercoat first.

14 Items

per page
Set Ascending Direction

14 Items

per page
Set Ascending Direction
  1. Johnstone's Trade Aqua Water Based Undercoat Brilliant White
    Johnstone's Trade Aqua Water Based Undercoat Brilliant White
    From £15.32 £12.77
  2. Recommended

    Johnstone's Trade Joncryl Water Based Primer Undercoat White
    Johnstone's Trade Joncryl Water Based Primer Undercoat White
    From £18.96 £15.80
  3. Johnstone's Trade Professional Undercoat White
    Johnstone's Trade Professional Undercoat White
    From £14.77 £12.31
  4. New

    Johnstone's Trade Aqua Guard Primer Undercoat Brilliant White
    Johnstone's Trade Aqua Guard Primer Undercoat Brilliant White
    From £20.03 £16.69
  5. Colour Match

    Johnstone's Trade Aqua Water Based Undercoat Tinted Colours
    Johnstone's Trade Aqua Water Based Undercoat Tinted Colours
    From £23.30 £19.42
  6. Johnstone's Trade Ultra Primer Sealer Brilliant White
    Johnstone's Trade Ultra Primer Sealer Brilliant White
    From £23.24 £19.37
  7. Colour Match

    Johnstone's Trade Professional Undercoat Tinted Colours
    Johnstone's Trade Professional Undercoat Tinted Colours
    From £19.27 £16.06
  8. Johnstone's Trade Wood Primer White
    Johnstone's Trade Wood Primer White
    From £28.81 £24.01
  9. Johnstone's Trade Aqua Undercoat Dark Grey
    Johnstone's Trade Aqua Undercoat Dark Grey
    From £26.64 £22.20
  10. Johnstones Alkali Resisting Primer
    Johnstone's Trade Alkali Resisting Primer
    From £44.83 £37.36
  11. Recommended

    Johnstone's Trade Advanced Stain Block Primer
    Johnstone's Trade Advanced Stain Block Primer
    From £32.92 £27.43
  12. Johnstone's Trade Professional Undercoat Magnolia
    Johnstone's Trade Professional Undercoat Magnolia
    From £17.47 £14.56
  13. Colour Match

    Johnstone's Trade Stormshield Flexible Primer Undercoat Tinted Colours
    Johnstone's Trade Stormshield Flexible Primer Undercoat Tinted Colours
    From £80.47 £67.06
  14. New

    Colour Match

    Johnstone's Trade Aqua Guard Primer Undercoat Tinted Colours
    Johnstone's Trade Aqua Guard Primer Undercoat Tinted Colours
    From £26.33 £21.94

14 Items

per page
Set Ascending Direction

What is Johnstone's Trade Primer?

Johnstone's Trade Primers are typically solvent-based primers, particularly the Universal White Primer, which can be used on interior & exterior surfaces. The properties of the primer allow for it to be used metal, plaster, and wood.

The main benefit of using this primer would be to prevent existing stains on a surface bleeding through or to give your paint a better chance to bond when you are working with a new/clean/unpainted surface.

What is Johnstone's Trade Undercoat?

Johnstone's Trade Undercoat is your stepping stone to prepping a surface before you apply a new colour or want to have the surface a certain shade to stop existing colours coming through.

This undercoat is solvent-based and provides a matt finish after drying in. It is traditionally used when you want to apply a glossy paint on the wall and would like to avoid discolouration or dull patches. The Johnstone's Trade range is a very popular one, as the undercoat cane some in white, magnolia, or pre-mixed to almost colour you like, the latter coming in handy when you know you'll be painting with more intense or dark colours and don't want white patches.

What's the difference between Johnstone's Trade Primer & Undercoat?

If you're not well-versed in paint vocabulary, it is all too easy to get confused over whether you need primer or undercoat. It can get even more confusing when you see products like Johnstone's Joncryl Water Based Primer Undercoat

You'll be glad to know there's a simple rule to follow when choosing primer and undercoat. If you have a blank surface, you need to prime the surface. If you need to wall to cover an existing colour, you need (under)coat everything.

In cases like the Joncryl product, it's simply a combination of both which professional painters would use if they wanted a water-based primer/undercoat which provides more coverage per litre and a quicker dry-in time.

What surfaces do Johnstone's Trade Primers & Undercoat work best on?

It all depends on where you're painting and whether you're looking to paint over something.

Johnstone's Trade Primers work best on:

  • Metals like iron & steel which haven't been painted
  • Masonry
  • Plaster
  • Wood

Johnstone's Trade Undercoats work best on:

  • Metals like iron & steel (great for fences)
  • Timber
  • Wooden features
  • Window Frames
  • New surfaces you want to apply gloss paints

What colours do Johnstone's Trade Primes & Undercoats come in?

For most people getting ready to paint, you'll want to stick with a simple water-based white undercoat for re-painting indoors. If you have a specific shade in mind and want it to look as good as possible, you may prefer to get a tinted undercoat instead. We also have Johnstone's Professional Undercoat (all colours) available in over 500 different pre-mixed colours. 

Find the right paint for your next paint job

Before you get started priming a surface, make sure you have all the tools you need. We have a dedicated cleaning & prep section, which has everything you need to prepare a room and help avoid any accidents.

If you need help finding a specific primer, undercoat, or any paint at all,  contact The Paint Shed directly, and we'll be happy to help.