Damn...
Couldn't pay via Paypal and wrote a mail to SilverGateArtifacts (as asked in the merch-section) about 9 or 10 days ago. Still wait for an answer... and now shirts size M are gone... look ridiculous wearing L- or XL-shirts...
Seems like I'll have to wait for new shirts... (Will there be some in near future?)
I answer every email that is written to Silvergate Artifacts. Usually within 24 hours. So either you got a response, or the email never made it to me. Sorry.
There are definitely some other designs in the pipeline. I hope to have them up within a month.