http://www.dodgeandburn.com/collections/shop/products/six-by-seven
I have got one and found that the textile quality is good and it looks cool. Below are two snapshots with my 645N SLR camera (taken with my *Pentax* K-5 + DA35):


Btw, the original Pentax 6x7, together with the original Pentax 645, are recognised as one of the milestone cameras of Pentax by AOHC whilst my 645N is recognised as a masterpiece. So, why not a 645 T-shirt also? Besides, I would want more colours of the T-shirt instead of only that light cyan colour for the background to "select" from, nonetheless.
Related:
True Fanboyism!
20 Millions of Pentax Cameras in 2013
The 645D Kit (Lens) Got Delivered to an End-User, Finally!
Dr. Pad Srivastava · 597 weeks ago
I am a Pentaxian: Asahi Pentax Spotmatic; Pentax LX and Pentax Super Program. Who is Rico - basically nothing. What about Pentax - well it used to be one of the big Five. The legendary Spotmatic, don't forget Pentax LX of 1980/1981. Pentax has done lot of innovation in photography. My suggestion to all Pentaxians world-wide (and there will be many). Let us all chip-in just a little money and invest in Pentax new products and research. Let Rice High take the lead on this. Let us bring the Pentax to its past glory and plus more. I am sure that Pentax can do it.
Jac · 597 weeks ago
Padmakar Srivastava · 495 weeks ago
str4nger · 597 weeks ago
PentaxWhy · 597 weeks ago
pentaxk01 · 597 weeks ago
quite good color and feel, one of few t shirt design showing pentax camera.