Many denimheads know that back in 2007, Levi's slapped a number of lawsuits on many Japanese Repro brands including, Sugar Cane, Studio D'Artisan, Iron Heart and Samurai amongst others. Another company that was forced to make subtle changes to their design is Pure Blue Japan. PBJ jeans were made featuring a Blue Tab on the back right pocket since their inception around 1997, until 2007 when they along with the aforementioned brands, had to make changes to their design to adhere to Levi's Cease and Desist letter.
Original PBJ Blue color Reyon Tabs, circa 1997 - 2007 (Image borrowed from user Shishido on Superfuture)
So all Pure Blue Japan jeans that were produced since 2007 feature the Indigo Leaf logo that has become synonomous with the PBJ brand.
More recently though, PBJ have changed the design of the waistband leather patch. Due to some issues with using the full name 'Pure Blue Japan' on the labels, the PBJ brand have opted to use the name of their umbrella company, Syoaia, on the new and refined leather waistband patches.
The new Lambskin Waistband Leather patches by Pure Blue Japan, featuring a Shokunin (Artisan) dipping jeans into a vat of indigo dye. These new patches are seen on all new production models after June 2012.
The original Pure Blue Japan Waistband Leather patches had the full name, 'Pure Blue Japan' embossed next to the artisan.