Level difference in patio - advice

[Leedslad]

Hi
my patio project is ongoing and I'm currently clearing the existing garden before my type 1 arrives next weekend. My design is to basically have new 450 slabs about 3m deep from door, as existing but a couple more rows. It then drops by about 50mm to a gravel area and a path to side leading to the gate. To avoid a big relevelling exercise I have decided to keep this level drop whilst redoing the gravel area with slate chippings. However I needvto know how to do this right, my thought is to dig down the depth for the first area of paving and add type 1 before then doing the path at lower level up to the gate. However would this not expose the upper level path materials ? Do I simply put some edging under the last slabs before lower level or is it ok to be exposed?

[lutonlagerlout]

normally you would have a course of bricks or an edging to differentiate between the 2 levels
just something to make that 50mm drop
you are on the right tracks mate, keep asking
LLL