Work shirts are not interchangeable. The shirt that's right for a finish carpenter in October is wrong for a welder in any month. Three categories cover most trades, and the differences matter.
Flannel. Cotton or cotton-blend, brushed for warmth and softness, usually plaid because the dye process for plaid hides wear better than solid colors. Flannel is for cold-weather, low-flame-hazard work — carpentry, general construction in cool weather, anything where warmth and movement matter and there's no spark or flame risk. Carhartt's Hubbard and Rugged Flex flannels are the workhorses; they hold up to seasons of regular wear and machine washing.
Flannel weight matters. Lightweight flannel (under 6 oz) is for shoulder-season layering — September, October, April, May. Mid-weight (7-9 oz) is the all-around work flannel, good as a primary layer in cold weather and a layer in cooler weather. Heavy flannel (10+ oz) is jacket-substitute territory, comfortable down to about 30°F as a top layer.
Duck canvas shirt. Cotton duck, the same fabric family as the iconic chore coat, made into a shirt. Heavier than flannel, more abrasion-resistant, a cleaner aesthetic for trades that interface with customers. Carhartt and Wolverine both make canvas shirts — the Carhartt Rugged Flex Duck Shirt is the most common one we sell. Canvas shirts are warmer than they look because the tight weave blocks wind, and they hold up to brushing against rough surfaces in a way flannel doesn't.
"If you don't need FR, don't buy FR. It's a hazard rating, not a quality rating."
Canvas is right for general carpentry, roofing in cooler weather, anyone working outside in wind, and anyone who needs to look a step more put-together for client interaction. Not great for hot weather — duck canvas doesn't breathe like flannel does.
FR shirts. Flame-resistant button-up or T-style shirts for trades with flame, spark, or arc-flash exposure. Welders, electrical workers, oilfield, refinery, anyone whose insurance or safety officer requires F1506 compliance. Carhartt's FR line covers most needs. Costs roughly twice what a comparable non-FR shirt costs because the fabric (Nomex, FR-treated cotton) is more expensive to make.
If you don't need FR, don't buy FR. The fabric breathes worse than regular cotton, costs more, and doesn't look or feel different enough to justify the price for trades that don't need the rating. Some guys buy FR by mistake thinking it's a quality upgrade. It's a hazard rating, not a quality rating.
If you do need FR, don't substitute. A regular flannel shirt under your FR jacket defeats the protection — when the jacket fails in an arc-flash event, the cotton flannel underneath ignites and continues burning on you. The base layer has to be FR or natural fiber under flame conditions. This is documented in NFPA 70E.
We stock all three categories in standard sizes. Walk in, tell us your trade, and we'll narrow it down — usually in five minutes.