Single Two-Tie (S2T) is another name for Summer and Winter. With this eight shaft threading, I am weaving on opposites without tabby. This sample is to let you see the difference between tabby and background and pattern.
This is what tabby and background looks like on my S2T warp. The top solid pink and black rows are tabby. Over one - under one. The next pink rows are solid pattern. The next pink/black rows is showing you pattern (pink square) and pink/black background. The solid black is what happened when you don't use two different colors. Your pattern doesn't show. And of course those last few rows are tabby again.
This is one of those things that is easier to understand in person. So hopefully I haven't confused you too much.