Hi, some pens retain the transparency of the material they are made of and others lose it, why?

Translucency is a property that depends upon the condition of the surface of the material and the light transmittablilty (?) of the material itself.

If a pen, or whatever, is scratched, the scratches interfere with the ability of light to enter the center or deeper parts of material, or whatever is "translucent" in the first place. The more scratches, the less light gets into the material and there goes the translucency.

Or, that's what was explained to me by a gem dealer when I asked why a moonstone (a "soft" stone to be sure) wasn't as "glowing" as it was when I first acquired the ring. Also, due to the hardness of diamond, the difficulty of scratching the stone is why they stay "sparkly" for so long. But, even diamonds will get scratched. Pens on the other hand, don't stand a chance when used often in environments where they can scratch.

So, if you've got a lovely translucent pen made of some sort of translucent resin-type material (think Visconti, which is my personal favorite "gold standard" for translucent) the more it is scratched, the less it will "glow" in the light.

But I could be wrong.

Yep that makes a lot of sense.

et