1. Sebago potatoes are a particular type of potatoes in Australia that are perfect for making wedges because they become nice and fluffy on the inside and crunchy on the outside.They are the common dirt brushed potatoes you can get everywhere. DO NOT use desiree (the red ones) - these are waxy, suitable for potato salad.
If you are in the US, russet is ideal. Yukon Gold is not suitable. For the UK - Maris Piper is a good all rounder which is suitable and readily available in all the supermarkets.