Custom made!
I designed it and got it printed in Estonia.
Technically, you just need any printer printer who can get die-cut blade manufactured to you and glue it together.
Quite similar is used by IOPS, where cover is dvd size, with hole in front cover, so it displayed the booklet that is inside the cover.
Of course, to get specific kind of carboard, right kind of lamination and all that, its up to good contacts.
Regardless are we talking about this particular cover or about printing art related things, I would strongly encourage people to even talk with local printers and businesses who may have shitloads of options if someone would just bring in some business.
