I have some large Italian Porcelian floor tiles but unfortuately they have been packed tightly for some considerable time and now that I have unpacked them the surface of the tiles have a chalky inprint of the rear of the adjacent tile. This washes off easily with water but leaves a "shadow" of the tile underside gridlines that can been seen in certain lights at some angles. I am not sure whether the tiles have been "etched" or whether they are stained. As I have 80m2 I am reluctant to use them if this cannot be removed or has damaged the tile so that any spills will be easily absorbed by the tiles across these marked areas.
Has anybody come across this befre and is there a remedy