could add two borders to add size.

I think if you use a sashing you're going to lose part of the design that your strips make. But if you do decide on a sashing I'd go with the black or even a deep navy blue.

As for a border, if you're doing one and have lots more scraps left, I'd do a piano key border.

I'd move the left side column of blocks to the top or bottom, making it rectangular and more "planned" looking; also, in my opinion, I would add white sashing between all the blocks; a white border and a color binding. To me, that would sing! Your quilt is marvelous!

This is how I would do it.

Check out this string quilting page. It is a primer but has pictures of different settings and looks. I like it without the sashing best. Good luck. http://www.quiltville.com/stringquiltingprimer.shtml

This is a beautiful quilt. I agree with others it doesn't need sashing but if you really need it I think black would be nice. I like black in a quilt.

I like it without sashing. Depending on who it is for would make the choice of border color easier. I would pick up one of the dark colors in the squares.

If you use a light color (all the same) for the center of the string blocks it kinda makes its own sashing and design. Haven't done one yet but have seen one and I really liked it. It didn't have sashings between the blocks and it looked really nice.

I like this without the sashing. It's easier to see when you see a finished quilt, isn't it. aaaaaahh..the wonders of quilting. LOL

A good formula to use is make the sashing 1/3 of what your blocks are. For example: 12" block would use 4 1/2 " sashing. Or if you have 8" blocks, you'd use 2 1/2 " sashings.