What is this called
 

Saw (on pinterest) Hasts but they had a one inch strip of black fabric between the two HST parts, to look like stained glass. What is the name of this tec. I know it but I'm having a senior moment aka brain dead.

Do you mean sashing?

No I don't think so as the piece is only cut 1 inch wide so only 1'2 inch shows between the two hst pieces. I know I can't cut two squares and sew either side of my pencil line and make two hsts at a time. Kinda looks like leading as on stained glass. Trying to find out how to do this.

in this area we just call it stain glass

You mean something like this?
http://quiltingdigest.com/this-scrap...possibilities/

Jenny Doan has a tutorial on Youtube. The Lattice quilt.

https://www.youtube.com/watch?v=0QNUkLoGQY8

Sorry, that is not the one. It looks like leading between the long sides ( for lack of a better description) of the 2 triangle pieces

I don't think there is a specific name for this technique, but it mimics the effect of narrow bias tape (which is sometimes used for the leading in stained glass quilting).

I would have said sashing or to simulate leading, but apparently not what you seek. The best example of this I have ever seen was shown on this board in work done by Deb Cavan. She couched black yarn where the leading would be. I believe that Deb's surname is Cavanaugh.

Yup, stained glass. Possibly foundation pieced, like this one:
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