Branding a glow stick is a backlighting problem, and it is nothing like branding a pen.

Why solid ink fails

A glow stick is read in the dark, lit from inside. Ink printed as a solid fill on the tube stops the light passing through it, so the logo appears as a dark silhouette in a glowing tube.

At small sizes that is fine and even quite smart. At any real size it looks like a fault — people read it as a stick that has partly failed.

The two things that do work

A printed paper or film sleeve around the tube. The mark is on the sleeve, the glow surrounds it, and you get a crisp readable logo with light on every side of it.

Or open line art printed directly on the tube: outlines and thin strokes rather than filled shapes, so the glow comes through the gaps. This looks better than it sounds and it is the more premium of the two.

Design for backlighting

Open the artwork out. Increase stroke weights slightly and drop internal detail. A logo with fine counters and tight spacing turns to mush when light is coming through it.

Reduce the number of colours to one where you can. Two-colour printing on a curved translucent tube has registration problems that a flat substrate does not.

Always look at it lit

Ask for the mockup with the stick activated. Unlit, every option in this article looks roughly identical and none of them tell you anything.

Also pick the glow colour for contrast with the print rather than for brand match. Green is brightest, so dark line art reads best on it — and it is very often not the brand colour, which is a conversation worth having early.