I have laid some natural limestone floor tiles, very pale, porous and
open grained. I haven't grouted yet and I am thinking I should treat
them with something before I drag coloured grout across them, which is
the recommended procedure. I left topps tiles without buying their
sealant already shocked at the price of all the 'extras' . I wondered if
I might use something cheaper, since this is only a little patch of
stone floor in an outbuilding and not an area of heave wear.

So what is a stone sealer? like a varnish? synthetic? oil? PVA? Acrylic?
wax? What would enhance the appearance of my limestone and make it
easier to clean? preventing the grout from staining it while allowing
the grout to stick itself in the joins?

TW