Tunica interior, subucula, or colobium, were undergarments worn during Ancient Roman times. fascia, a sort of corset, then a tunica interior (subucula, interula), and above it the indusium, or tunica indusiata. From 753 until 323 B.C. it was the innermost

tunic A tunic is a garment for the body, usually simple in style, reaching from the shoulders to a length somewhere between the hips and the knees. The name derives from the Latin ''tunica'', the basic garment worn by both men and women in Ancient Rome ...

(undergarment). They were made of wool and later silk or cotton and the width was consistent from top to bottomComplete Costume Dictionary by Elizabeth J. Lewandowski page 300

References

Roman-era clothing Undergarments {{clothing-stub