At first, I just used one 'hole' on each ZT. However, after awhile I added additional holes. Sometimes all of the holes viewed the same materials, as shown above. Later, each hole viewed something different.
After looking through holes, I started wondering what would happen if something came through the holes? This led to a variety of attempts to show this.
Hmm, looking through at a different level, passing through from one level to another, that left just one thing to explore, in my mind at that time -- floating above.
Actually, what I found was that "looking thru" and "floating above" were basically the same, The only difference came with the shading. When 'looking thru', the deeper item is shaded, and may even have a shadow cast on it by the more superficial tangle. When 'floating above', the floater casts a shadow on the layers below it, and the floater is brightly lit.
Throughout the months of February and March, I drew numerous ATCs, ZTs and ZIAs which made use of all of these techniques. Here are a few examples.
That's all for now. More to come in the future. :)