It is virtually invisible once dried. Perfect on pale limestones, it will not darken the stone.
It can also be used as an undercoat for Stoneseal to reduce the darkening effect, or as a top quality seal on its own .
It is very low viscosity solvent-based impregnating treatment for most porous surfaces - from low porosity stone to highly porous wood and concrete. It has no (or at most very slight if heavily over applied) effect on the surface texture or appearance of the substrate.
Based on the latest chemical technology, the cured product will protect the surface from penetration of aqueous liquids and stains and give effective protection from oils and similar liquids; resistance to solvent-based attack depends on the solvent - alcohols and aliphatics are well resisted, aromatics and esters will attack the product in due course.
Resistance to u/v and general sunlight is excellent but damage to and erosion of the substrate by u/v and other natural weathering will eventually reduce the effectiveness of the protection on low porosity substrates - more porous substrates will be better protected as the active components will have penetrated more deeply.