Iron Heart's ultra heavy flannel (UHF) shirts are woven with wild-grown Aspero cotton from the foothills of the Andes, to give them a substantially thick, yet noticably soft hand, making these some of the most premium, well made flannels on the planet. The interior is double brushed, while the exterior is single brushed, giving them an extremely cozy feel, and resulting in a very soft, heavy, thick, warm, and windproof flannel shirt. 

• 100% Aspero cotton
• 12oz Japanese ultra-heavyweight flannel - navy/black Ombré check
• Cheese dyed (direct dye)
• Work shirt
• Fabric single brushed on face and double brushed on reverse
• Black tonal stitching
• Black cat's eye buttons
• Classic patch pockets with button fastenings and pen holder
• Single and double needle stitch construction
• Straight back yoke
• Felled internal seams
• Side seam gussets with chainstitch run-off
• Yellow bobbin thread
• One-washed for shrinkage, but could shrink up to half a size with continual or very hot washing/tumble drying
• Made in Japan
• Size up from your usual North American size