Linen is cut for a mattress height. If you change the mattress later, the skirt and the fitted sheet tell on you.
We like to decide foam or spring with the coverlet in the room. A tall, plush mattress wants a different drop than a low, firm one.
If you already have a bed you love, we build the mattress to that carcass. The linen then follows the number we actually made, not a catalogue depth.