365 nm vs 395 nm: Which Wavelength Do You Need?

Both wavelengths are UV-A, and both will make something glow. They do not make the same materials glow at the same strength. Picking the wrong one is the most expensive mistake on a UV project, because the fixtures are otherwise doing exactly what the datasheet says.

395 nm is the venue default

Fluorescent paints, fabrics, tape, décor and most party or escape-room treatments are formulated for long-wave UV around 395 nm. It is also the more efficient of the two in radiant flux on these fixtures: where the datasheet prints a pair, the higher number is the figure to plan a 395 nm show around.

A sports field, a stage wash and a dual-source downlight in a themed room should start at 395 nm unless a designer has specified otherwise.

365 nm is a specification, not an upgrade

365 nm is the right lamp when the ink, adhesive, coating, mineral or inspection standard is written for it. It sits closer to the visible edge of some NDT and curing processes. It is not a brighter version of 395 nm. A 395 nm room treatment under a 365 nm flood often looks dull, and a 365 nm adhesive under a 395 nm spot may not cure on the manufacturer’s cycle.

How to decide in one email

Send the material name or the TDS, the viewing distance, and whether people will also see the lamp (395 nm leaks a little more visible violet). If you do not have a TDS, send a sample of the paint or fabric. We will match the bin before anyone cuts a purchase order.

Every modular series on this site is offered in both bands. The dual-source downlight is 395 nm only. The spot and the line light follow the job.