Japan Blue 13.5oz 4th Type Denim Jacket (2021)

Size Guide
Made up of Côte d'Ivoire cotton, this one of the best value denim jackets you can go for!

The design of this 4th type denim jacket is inspired by the vintage Levi's denim jacket from type 1 ~ type 3 and JB has taken this to their MADE IN JAPAN level with especially developing their denim fabrics using hand-picked Côte d'Ivoire cotton. It has a beautiful brownish hue and fibres with an irregularity that enhances the texture in the denim itself.

With time, this denim will fade to a soft contrasted look and gain a brownish hue as the natural colour of fibres shines out amongst the shades of grand indigo.

For a more practical all year round use, this one has waist pockets to keep your hands warm. You can always cuff up the sleeves and adjust the waist fitting thanks to the adjuster straps. The WWII style doughnut buttons add a tasteful vintage vibe as well!

Enjoy the beauty of faded denim with time!

  • 100% Côte d'Ivoire Cotton
  • Japanese 13.5oz green & yellow ID selvedge denim
  • Genuine indigo dyed
  • Twin chest pockets
  • Twin side pockets design
  • Copper buttons
  • Cowhide leather patch
  • Adjustable waistband
  • Slim fit
  • Once Washed (Minimal Shrinkage)
  • Made In Japan

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How We Measure

Pants and Shorts


With the major buttoned up (i.e. the top button) open the jeans and lay them flat, like shown. Measure from the front where the major button closes to the back belt loop. Double this measurement to find the waist measurement.

The way we measure the waist is different from the 'Side to Side' technique. If you are used to the 'side to side' technique you can roughly roughly downsize by 1 inch.

For example, 'side to side' measurement for The Flat Head 3002 waist is 28inch and using our method measures at 29.25inch.

Front Rise:

With the jeans lying flat measure from the crotch bar tack to the top of the waistband. 

Back Rise:

Spread out the crotch so the bar tack is visible, then measure from the crotch to the top of the waistband.


One inch down from the crotch, measure flat across to the other side.


Flatten the leg and measure along the inseam from the crotch to the leg hem. 

Leg Openning:

Measure straight across the hem from side to side.





Lay flat then measure from the shoulder's edge to the other shoulder's edge.


Lay shirt flat and measure from pit to pit.

Sleeve length:

With the sleeve flat measure from the shoulder to the cuff.

Arm hole openning:

Measure from the shoulder down to the pitt.

Vertical length:

With the shirt facing down, Measure from below the collar to the bottom hem.