To clear up a little confusion, a skirting board goes around a wall at floor level and an architrave is the moulded trim around doors etc.
Two common types are available Torus and Ogee.
This is what a Torus skirting or architrave looks like in profile. Torus skirting is usually available in 119mm & 169mm width. Torus architrave is available in 69mm width.
This is what an Ogee skirting or architrave looks like in profile. Ogee skirting is available in 119mm width, ogee architrave is available in 58 & 69mm widths.