Here is the back of the block:
[ATTACH=CONFIG]301617[/ATTACH]
And here is how the front looks with the overlap. This part had me worried until I joined two halves. This part falls into the seam allowance and is hidden.
[ATTACH=CONFIG]301619[/ATTACH]
As for starch, I was warned against it until all the pieces were joined. I remember someone mentioning that the dragging of the iron on the triangles with starch on them could distort them before they were pieced. I didn't personally need it, and was hyper vigilant to keep from stretching the edges.

I starch before they are triangles :)

I agree that starched fabric is easier to handle. If there is a thing as too much starch, I probably use too much. (I love the smell of my starch since I added some lavender essence!!)
I just got in a hurry when I started this and didn't even consider it. The warning came pretty late in the game for me (after half hexes, before rows were made). But, where I starched the rows I have put together...I think it lays much nicer than the parts that are not starched.
I may try starching from the beginning of my next project and see if I notice a difference in cutting.

Beautiful.

FYI .... I prewashed, and starched first. All went together slick as can be. And the bonus ... no fraying (along with no stretching happening. It was probably the cleanest back of a quilt I've ever done! .... and smooth!

When stacking the fabric ... I was taught to stab a large pin (those flat flower headed ones) thru a place where the design began and ended eg. where the leaf joined the stem or when the pink flower joins a green leaf etc. Then do that in a few other places. Pins are just stabbed thru at this point. Hold them straight up and down, then take another pin, and pin it in several places ... this two step method , helps keep the fabric from shifting and ensures you get it all lined up nicely when pinning.

The starch ... helps in this step to allow the fabric layers to slide around for you as you do this, rather than how the layers would stick together and not lay smoothly without.

I am getting ready to start a OBW. What kind of starch do you use?

I use spray starch as that's all that I can get here.
And it's getting hard to find now too, for some reason.

We can get Mary Ellen's Best Press, which would be OK ... I've never used it!

I recently found Niagra and Faultless starch in a non-aerosol spray at the grocery, of all places. It smelled a little funky, that's why I added lavender, but BOY does that stuff work! It also seems less sticky than the canned kind, IMHO.

I think these obw are wonderful. I like the colors, the pattern and all.
I would be proud to say that I did them.

Thank you for taking the time to explain this to me. I think seeing the picture is a big help. I will try stacking the way you do. I did buy a 60o ruler today and hopefully all of these things will be the answer to my making a beautiful stack of hexes like your.. I may try the starch, but think I will wait and see how my next try works.