Monograms

When you have a monogram, is the Last name initial supposed to go in the middle?

I am buying personalized stationary for my grandmother. The cards have the 3 letters on them and the one in the middle is the largest.

If the letters are all the same size, is it then first, middle, last?

last inital always goes in the middle

(I think.....)

yes

if they are all the same size its first middle last