Since I saw where you had posted the same question on the Flames of War forum, I'll give the same answer I just posted there:
_________
As you can see from the photos from the link below, sometimes the plates of the SN-42 armor showed a shine; in others, they are dead flat. The figures on the box cover show both "fresh" and worn armor plates: a nice job. The actual color of the paint on the plates no doubt varied some, especially with wear.
link
If you're talking about the artwork on the box, the only thing I see that might look like fabric is the "neck roll" padding of the lining and suspension system; it *was* fabric, and as you can see from the photos, it might or might not vary more or less from the color of the plates.
The plate from Armchair General looks like it was interpreted from a fairly worn surviving example. I see no problem with the Battlefront box art portraying something that looks quite new, with a very matte finish. And the paint work on the figures is just cracking.
___________
Look carefully at the individual painted figures from the box or the Spotlight article:
link
Some of the plates have been painted with varying nicks and scrapes or entire worn sections, which give the appearance of shining. Very well done, for 15mm.
Allen
paints 
