I received this report from reader (thanks M.) regarding a new surface finish on all new Sigma lenses:
After having introduced new lenses in 2010, Sigma also uses a new surface for their lenses. To date Sigma was known for their velvet and furry surface, but looking at the 85mm 1.4 and 70-200mm 2.8 OS for example you can see the new matte and smooth finish. After having dealt with this topic for a while I found some reports from people who recently bought some Sigma lenses new that where introduced several years ago - for example the 30mm 1.4, the 50mm 1.4 and the 10-20mm 4.0-5.6 - that also have the new matte and smooth finish. In some photo and electronic shops in Germany you can take a look at different versions of the Sigma 30mm 1.4 standing side by side inside the showcase. One with the old velvet and furry surface, one with the new matte and smooth finish. It seems that Sigma is changing their complete production regarding the finish.
I contacted Sigma regarding the new finish of their lenses that seems to be transferred to their older lenses as well. They are really changing their production regarding the surface. Here is their original answer in German:
"Guten Tag,
Die Geräte aus unserer aktuellen Produktpalette sollen nach und nach mit diesem neuen Oberflächenfinish ausgeliefert werden. Wann welches Gerät allerdings ausgeliefert wird können wir vorab nicht sagen."
In English:
"Hello,
All the devices from our current product lineup will be shipped step by step with this new surface finish. But we cannot say in advance when which device will be send."
After a quick Google search, it seems that several websites have already reported this new finish on Sigma lenses.