Glow sticks are bought on a duration number and judged on how they looked at the event. These four things decide the second part.

Brightness and duration are one budget

The reaction holds a fixed amount of energy. Concentration decides how fast it comes out. Brighter is always shorter, and there is no formulation that escapes it.

So decide what the moment is before you shop. Thirty spectacular minutes and twelve dim hours are two different products, and buying the wrong one is the most common mistake in this category.

Read a duration claim properly

A twelve-hour rating means measurable light at twelve hours. It says nothing about brightness at hour eleven, and the curve falls steeply in the first hour and then runs long and dim.

The useful question to ask a supplier is not how long it lasts. It is how bright it is at the end.

Temperature is not a detail

The reaction is chemical, so heat accelerates it and cold slows it. A box in the sun behind a marquee spends part of its life before anybody snaps a stick.

The corollary is the trick every event crew learns eventually: keep them in a cool box on the day, and they will visibly outlast the ones that sat in the van.

They age in the packet

Foil-wrapped and stored cool, glow sticks hold for years. In a hot store room they are noticeably down within one.

That makes the big price break on three years’ supply a false economy for most buyers. Ask for the manufacture date on the outer — if a supplier will not print one, that is informative.

And check how the branding is printed

A solid ink logo printed straight onto the tube blocks the light behind it and reads as a dark patch. A printed sleeve, or open line art rather than a filled shape, lets the glow through.

Always ask for the mockup lit. Unlit, every option looks the same and none of them look like what you are buying.