Hi everyone,
Does it need to be sealed Presealed polish porcelian?
In tile shop they gave me sealer and said it will be better to seal them(even it is presealed).
I went for advice to another tile shop and they said i only make worse for tiles.
So what do You think?

Thanks For Your Help.

Get a regular felt tip soluble marker pen (not permanent) & do a small test mark on the corner of one of the tiles that are assumed treated with the sealer, if the mark is cleanly & easilly removed with a tissue & water it is fair to assume that the preseal is doing its job it would though do no harm at all though to apply a second treatment...

IMPORTANT AFTER THE TREATMENT GIVE THE TILES A GOOD 5 HOURS + TO DRY THE TREATMENT IS ABSORBED INTO THE TILE & MAY APPEAR DRY ON THE SURFACE BUT IS NOT FULLY ABSORBED FOR A GOOD FEW HOURS.....

Good luck Phill

The polishing process on porcelain opens up minute pores on the tile surface, which can sometimes mark easily and be almost impossible to remove (don't ask me how I know this). Some polished porcelains mark easily and some don't - testing as suggested is certainly the less aggravating way of finding out