Yes, inside and outside labels are $2.50 per shirt! For either type, the maximum print area is 3x3 inches. Check out examples of custom inside and outside labels in this branding guide.
Inside labels are available for select apparel products with a removable "tear-away" label. Find unisex and men's tshirts with a tear away tag here, or use the left toolbar to search for women's shirts.
Outside labels are available for all other brand t-shirts (except racerbacks) that don't have a removable "tear away" label.
When you submit an order or sync a product, you'll see the option to upload an inside or outside label print file, depending on the shirt model. You can download print file guidelines for inside labels here.