Every guide to helmet decal finishes shows you swatches, lined up on a white background, all of them looking great. Nobody orders a helmet to sit on a white background.
The finish that wins on a proof can disappear on the field. What decides it is light: when you kick off, what's lighting the field, and what your shell is already doing with that light.
There's a second problem. Most programs treat shine as a scale where more is better, and matte as what you pick when you don't want anything special. Both are wrong. Sort out what each finish does with light and the rest of the decision gets simple.
How much shine do you actually want?
A decal does one of three things with the light that hits it, and they are not points on a single scale.
Specular reflection bounces it back at a single angle, like a mirror. That's chrome. Stand in the right spot and it blazes. Stand somewhere else and it reads as flat gray.
Diffraction splits light into its component colors. That's
