Padstacks

Hi

Up to now all our designs have been 2 layer, with our interlayer padstack undefined for thru hole parts and vias.

We are considering doing a 4 layer or perhaps a 6 layer design.

Do I need to create a seperate padstack for each number of layers?

Then the question becomes do I still need to keep the orginal padstacks for any new 2 layer designs?

Thanks