Same wolf as before.

If I were doing a square or rectangular window, I have wooden boards with true-square backstops to build the window in. All of the pieces would be held in place with right-triangles and nails.

I can't do that with the organic forms so I need some way to hold them all in place while I solder. Some people use t-pins around the border, but that doesn't hold the peices together as accurately as I like. I tack all the pieces together with tiny strips of blue making tape.

In this case, because he is staring at me, the little bits of tape make him look like some mad scientist stitched him together from a bunch of wolf pieces.

As a side note, the boards he is sitting on are ceiling tiles. They are fire resistant, which makes them perfect for soldering, and about a dollar each, so when they get gunged up I can just toss them and use a fresh one.