Light is the variable that most directly shapes resin production once genetics are fixed. Plants from high thc strain seeds respond to intense light during flowering by producing denser trichome coverage, and some growers add a modest amount of UV-B in the final weeks to push that response further. Insufficient light, by contrast, leads to airy buds with a fraction of the expected potency even from excellent genetics. Matching lamp output to canopy size is therefore one of the first things to get right.