IHSH-428-GRN - Ultra Heavy Flannel Vintage Check Work Overshirt - Green

The Iron Heart Ultra Heavy Flannel is the definition of what the brand stands for: rugged construction, unmatched warmth, and uncompromising comfort. Woven from a 12oz Aspero cotton - a wild, naturally occurring cotton from the foothills of the Andes - this flannel offers a dense, structured hand that softens beautifully over time. It’s single brushed on the face and double brushed on the reverse, creating a thick, wind-resistant fabric with surprising softness. The reactive-dyed twill weave ensures the color stays rich and fade-resistant through years of wear.

Designed as a true overshirt, this cut delivers the perfect balance between heritage workwear and practical layering. The relaxed fit, straight hem, and split side gussets make it ideal for wearing over a tee or sweatshirt, while details like chest pockets with a pen holder, a full button front, and reinforced seams speak to Iron Heart’s precision. Built by hand in Japan, this shirt is as functional as it is iconic - the kind of flannel that only gets better with age.

• 12oz Japanese Ultra Heavy Flannel
• 100% Aspero cotton
• Single brushed face, double brushed reverse
• Twill weave construction
• Reactive-dyed warp and weft for fade resistance
• Work shirt design with oversized fit
• Chest pockets with pen holder
• Straight hem with split side-seam gussets
• Button fastenings throughout
• Single and double needle stitching
• Bar tack reinforcements
• Chainstitched side seams, felled internal seams
• Made in Japan

Handmade by WORKS INC. in Japan

A variance of +/-.5" is within tolerance. 

Fit Notes: Tommy is wearing an XL in this piece. He rarely, if ever, says this, but he could wear a size smaller in this. The Overshirt is one of the first shirts to ever carry a boxy fit, so it makes sense. We would recommend buying your true size in this garment, which might be one size smaller than what you normally wear from Iron Heart. Tommy is 5'10," 162lbs with a 40" chest.