Koch-Chemie × COLOURLOCK COLOURLOCK "Blocker" barrier coat against bleed-through discolouration 1000ml

COLOURLOCK Blocker — barrier coat against discolouration on leather

What is COLOURLOCK Blocker for? — The Blocker forms an insulating barrier coat on leather that stops discolouration, bleed-through or dye migration from the base coming through to the surface.

COLOURLOCK Blocker is a dedicated barrier coat you lay down before dyeing or sealing to reliably stop discolouration and dye bleed-through. On tricky leather in particular – after pulling denim rub-off, over old repairs, nicotine staining or heavily contaminated surfaces – the Blocker keeps leftover pigment or dissolved dyes from showing through again later. That gives you a clean, stable base for a colour result that stays even over time.

• Effective barrier coat – Blocks discolouration, bleed-through and dye migration.
• Ideal repair base – Stabilises difficult substrates before dyeing.
• A must on problem leather – Perfect after GLD Solvent, heavy cleaning or degreasing.

Barrier technology & how it works

Blocker lays down a thin, transparent insulating film that stops any leftover dyes, oil residue or contaminants from deeper layers migrating up to the surface. That barrier is key when the leather has been heavily cleaned, stripped of colour or chemically treated beforehand. The Blocker stabilises the surface without sealing it the way a Top Coat does, and stays open enough for the following colour or finish products to grip properly.

Application, laydown & best practices

After a deep clean or using products like Degreaser or GLD Solvent, you lay COLOURLOCK Blocker down thin and even with a sponge or by spraying. Let the coat dry fully before you bring on colour, Leather Fresh or leather dye. On really critical jobs a second thin coat can make sense. What matters is an even laydown so the barrier effect stays consistent across the whole area. After that you can go on with the regular colour and finish build-up.

Results, uses & where it fits

Once applied, the leather surface stays colour-stable and free of discolouration coming back. COLOURLOCK Blocker is a perfect fit for automotive leather, furniture, bags and interior parts with a known bleed-through problem. It's not a cleaner, not a filler and not a Top Coat, but a prep product that goes in between cleaning and colour. On light-coloured leather especially, the Blocker is what gets you a clean result that lasts.

Common questions about COLOURLOCK Blocker

When do I need a blocker?

Any time you'd expect discolouration or dye bleed-through after dyeing.

Does blocker make sense on light leather?

Yes, on light leather especially it stops dark shadows creeping back later.

Can I dye straight after?

Yes, as soon as the Blocker has dried fully.

Does blocker replace the Top Coat?

No. Blocker is a barrier coat, Top Coat is the final protection.

Can blocker be used on all leather?

On pigmented smooth leather, yes. Not for nubuck, suede or aniline leather.

Last updated: 11.12.2025 — Author: Daniel (Detailing1)