spiders silk can't be synthesized very accurately. Carbon is much easier to integrate into 3D prints, it's very commercialized, and only 1-2 3D printers using carbon is available. Silk is much more complex:
They still don't understand the structure and lacing of the proteins very well. milestones of research demonstrate the technical difficulty of the task:
"Solid-State C-13 Nmr of Nephila-Clavipes Dragline Silk Establishes Structure and Identity of Crystalline Regions" 1994
"The molecular structure of spider dragline silk: Folding and orientation of the protein backbone"2002
"Molecular orientation and two-component nature of the crystalline fraction of spider dragline silk"1996
"Stretching of supercontracted fibers: a link between spinning and the variability of spider silk"2005
Spider silk is immensely complex, and contains multiop;e proteins woven together in specific patterns to achieve different elasticity and strength, and the spiders typically have mutliple glands for different types of silk, which use very specific pH gradients and complex chemistry and physics, which we can't match at all.
this page gives some info on recent industrial advances:
https://www.sciencedaily.com/releases/2017/01/170109124957.htm
it sais that you need 1000 protein fibers wound together to make a single spider's silk thread.
this page gives recent advance.
http://cen.acs.org/articles/92/i9/Spider-Silk-Poised-Commercial-Entry.html
For the moment, spider's silk is not commercially available for textiles or fibers, except for stuff taken out of a spider. A spider isn't heavy you can't print much from a spider :)
for the recent spider silk news, see here:
it's all research news as of summer 2017, not sales and business news. so... spiders silk can't be synthesized with volume and accuracy to compete in any commercial fields. Making some of the proteins found in the silk is only the smallest and easiest part of the puzzle.