With the sashing it looks more "artsy", without it it has a slightly more traditional blended effect, almost like a basket weave. I like both looks.

i like it both ways :)

with sashing. each block stands out a bit more.

Stunning blocks. Because it's for a grandson, I'd say sashing. If it were for me, I'd want no sashing.

I like it with a thin sashing - pops the quilt blocks. But, either way the blocks are beautiful.

Beautiful work you did. I love the fabric. I love the blocks with the sashing definitely!!

I like both ways.

Sashing for me too!

Hugs

Caroline

Hello

I too like the sashing!

Your colors are wonderful. The pattern while it is elongated triangles is very linear. You might like to try putting two blocks together to get a square shape and then set them wonky against a wide black sash for a very distinctive, unexpected look. Of course it would be larger and a totally different type pattern, but just a suggestion.