Wood varnish protects the surface without sealing the wood.

A conventional polyurethane varnish builds a continuous synthetic film on the surface. That film is hard and impermeable — it keeps water out, but it also locks moisture in, and when seasonal movement makes the timber swell and shrink the rigid film cracks, bubbles, and peels. The failure is the film.

A natural-resin wood finish works differently. Stand oil, castor oil, and natural resin esters penetrate the surface layers and cure to a weather-resistant, water-repellent finish that stays open-pore — water vapour still passes through, so the wood keeps regulating its own moisture. Water is repelled at the surface; vapour is not trapped, and there is no closed film to crack under the movement of the timber.

The result sits between a penetrating oil, which lives entirely inside the wood, and a film-forming PU, which sits on top. The surface is harder and more closed than an oiled finish — it takes more daily wear and resists weathering more aggressively — without giving up the vapour-permeability that keeps natural finishes durable on moving timber.

Timber outdoors in India faces an unusually hard combination: UV well above European norms, three months of monsoon saturation, and a dry season that pulls the moisture back out. Conventional film finishes crack under that cycling, because the film moves differently from the wood beneath it and the bond fails. An open-pore natural-resin finish lets the wood move without fighting a rigid film.

For facades, panel doors, heritage windows, jali screens, pergolas, and fences — vertical timber, weather-exposed but not foot-trafficked — LEINOS 260 and 266 are the correct specification. Choose 260, the solvent-borne system, where built-in IPBC sapstain protection or deeper penetration is wanted; choose 266, the water-borne system, for lower odour, faster recoat, water clean-up, and a far lower VOC figure (30 g/l). Apply at least two coats in the direction of the grain, above 15 °C.

Neither product is for floors, stairs, or decking that takes foot traffic — the TDS states this exclusion for both. Horizontal trafficked surfaces need a hardwax oil or a dedicated floor product instead.