With Shade, I’d order up a size, especially for shirts you plan on wearing without anything under it. The way that these shirts are finished varies, some are definitely made only for going under things, like the cap sleeve by Shade. The finished cap sleeve, however, is great by itself.
DownEast has been pretty true-to-size for me with “the wonder tee”, but I don’t wear it alone.
Some items mention not machine-drying, but I’ve not had problems.