THE FLAT HEAD Long Sleeve Indigo Knit Heavy Thermal

About this product

This Heavy Indigo Thermal from The Flat Head is built using a truly exceptional 23oz fabric, far heavier than conventional thermal knits. The yarns are rope-dyed with natural indigo at a historic Japanese dye house with over 130 years of expertise, leaving a white core that gradually reveals itself through wear and washing, creating dramatic, high-contrast aging unique to indigo garments.

Unlike standard thermal fabrics, this piece is knitted on dedicated machines capable of handling extremely thick yarns, resulting in a low-gauge, knit-like structure that feels substantial yet flexible. The texture is bold and three-dimensional, offering excellent stretch, moisture absorption, and breathability – making it versatile enough to wear as a spring knit or a cold-weather base layer.

Indigo-dyed ribbing is used throughout, ensuring uniform fading across the garment rather than isolated color loss. The neckline is finished with The Flat Head’s signature three-needle, one-off stitch construction, using thick cotton thread for long-term durability and a distinctive vintage look.

This is a statement piece rooted in traditional Japanese craftsmanship, designed to age beautifully and last for years.

Fit Notes: All Flat Head tees run smaller than your regular American size, and this ultra-heavy model fits even smaller than standard Flat Head tees. If you usually wear a size 42 in Flat Head tees, you'll need to size up to a 44 in this one. If you're not familiar with Flat Head or other Japanese brands, a size 44 in this model is between a US Medium and Large. In any case, as always, we recommend checking our size chart to ensure the perfect fit.

Description from Redcast Heritage Co..

Details

Brand

THE FLAT HEAD

Colour

indigo

Listed

At 1 shop in 1 currency

Last change

13 October 2026

Shops in Spain.