Gel Nails and Light-Cured Enhancements
How gel cures
Gels are oligomers that stay liquid until light activates a photoinitiator in the formula. UV lamps emit mostly in the 340 to 380 nm range; LED lamps emit roughly 365 to 405 nm. A gel only cures if the lamp's output matches its photoinitiator, which is why 'LED cures everything' is a trap answer. Only LED-curable gels are safe under an LED lamp.
Families of gel
Hard (building) gels are rigid and must be filed off. Soft gels are more flexible and soak off in acetone. Gel polish is a soft gel system of base, color, and top, removed by soaking, never by ripping. The inhibition layer is the tacky film left after curing; do not touch it with bare fingers, and wipe only the final layer with the cleanser the manufacturer specifies.
Curing discipline
Apply thin coats. Under-curing leaves uncured monomer that can cause contact dermatitis and service breakdown. Over-thick application causes shrinkage and a heat spike, the burning sensation clients report. Bulbs and LEDs weaken with age, so replace them on the manufacturer's schedule and keep reflectors clean.
The real occupational risk
Methacrylate allergy is the most common career-ending problem in this industry. Once sensitized, a technician may react permanently to acrylics, gels, and some adhesives. Keep product off the skin, never cure product that has flowed onto skin, do not rest your brush hand in the product, and wear gloves.
Rule of thumb
If the client feels heat, the layer is too thick or the lamp is too strong. Remove the hand, wait, then cure in thinner layers.