Before you try anything: always speak to a professional before cleaning, treating or applying any product to your stone. Every slab is different, and the wrong product can cause permanent damage. Contact us or a qualified stone restorer first.
Quick answer
Fine grey lines on porcelain are usually metal marks from cookware and come off with a non-scratch cream cleaner. True scratches through the printed glaze of porcelain are permanent, because the pattern only sits on the surface. Prevention matters more on porcelain than on almost any other surface.
First, check what you are dealing with
- Grey line, smooth to the touch: metal mark.
- Pale or white line you can feel: a real scratch.
What you need
- Non-scratch cream cleaner
- Soft damp cloth
Step by step
Rule out metal marks
Rub the line with a non-scratch cream cleaner and a damp cloth. Grey lines from pots and cutlery often disappear completely.
Assess what remains
Dry and inspect in raking light. A remaining line you can feel is a true scratch.
Ask a repairer
A porcelain repairer can fill chips with colour-matched resin; scratches through the printed layer cannot be polished back.
What not to use on porcelain
- Car polishes and cutting compounds.
- Sandpaper or scouring pads.
When to call a professional
A porcelain repairer can fill chips with colour-matched resin; scratches through the printed layer cannot be polished back.
Understanding scratches on porcelain
Porcelain is hard, but the decorative pattern is printed on the surface; polished glazes show fine scratches and matte ones pick up grey metal marks.
Porcelain problems are usually residue, metal marks, chips on edges, or scratches through a polished glaze.
A porcelain repairer can fill chips with colour-matched resin; scratches through the printed layer cannot be polished back.
Good to know
Grey lines on porcelain are usually metal marks, not scratches, and come off with a non-scratch cream cleaner. True scratches through a printed glaze are permanent.
Stop it happening again
Whether yours is large-format marble-look and concrete-look porcelain slabs, repairing it fixes today's mark; protecting it stops the next one. Our clear Stone Protection Film sits over the surface, so marks stay on the film, not the surface, and its self-healing top layer shrugs off fine everyday marks. Choose Gloss for polished porcelain or Matte/Satin for honed and matte finishes. The protection is identical. It is installed across Sydney with a 10-year written warranty.
How we protect porcelain · Honed vs polished stone · Scratches on every surface