Manufacturing such products isn't our business, so it's hard for us to provide high quality merchandise like that. We do have some items available through a 3rd party here:
https://society6.com/esotericsoftware
The black travel mug is decent and I use it every day. I tried the stickers and they were not great. I'm not sure about the quality of the other items.
We setup the media for the items and so that website pays us when someone buys an item. However, they give us only $0.40 per item, so it's basically nothing. Definitely don't buy items hoping to support us, instead buy them if they are items you would like to have.
I expect there are many online stores that can take pictures and make them into a shirt/etc. We are happy to provide the media, if that would help. You can find official and high quality media here:
http://esotericsoftware.com/branding
If anyone knows which websites provide particularly high quality items, we'd be happy to set up the items similar to the site above so they are easier to acquire. In my experience commissioning Spine shirts to wear to events, the printing quality varies but the bigger problem I found is that the shirts are low quality with poor fitment. I have a couple in my closet I don't wear for that reason. It's be great to have a Spine shirt that fits well so I can actually wear it!
