Some days start frosty and heat up fast. In that weather, a long-sleeve heavyweight cotton work t-shirt is the answer when picking a foundation layer. But our Grit-squared is not like all the other tired and worn-out t-shirts on your floor. Itâs heavyweight seven-ounce cotton and strong cover-stitch construction are made to endure the hard work of long days on the job-siteâno matter what trade youâve mastered. Washed, weathered cotton looks seasoned and reduces friction on skin. Yet what rates most with us is the armpit ventsâcooling the body down and cutting down stink even as the heat index spikes.