Joining backing
 

I've learned so much from the questions ive posted here before.
Now...I cannot find any 108" wide backing fabric to match so I will have to piece tieback.
Do I make my joining seam vertically down the back or the seam across horizontally?
Terry

Be sure you cut off the selvedges, use at least a 1/2 " seam, press it open. Probably seam it vertically if you are having it quilted elsewhere. Be sure to backstitch at each edge to secure the stitching.

I think it is your preference. A vertical seam is the most common I think. I will often do a little piecing on the back like adding in a couple of blocks like on the front or piecing together several complementary fabrics so have seams in the back going both directions.

I like the shortest seam....if i can make it fit with the seam running horizontally, that's usually what i'll do.

I like to make a pattern strip vertically on the back. Either left over blocks or squares of the fabrics used in the front. The pattern strip is between the backing fabrics so if the backing has a pattern, there is no pattern matching.

What I've been doing lately on the back of my quilts is putting a panel about 3' x 4' (varies by quilt) in the center and then adding the sides and top and bottom.
It all started when I was doing panel quilts. I take the 3 x 4 panel, batting and backing and quilt it like a small quilt,
square it up and add front and back to one side, spray baste the batting in
and quilt that side, then I do the other side, then top and bottom.
I don't have the room to quilt a large quilt so this works great for me.
What ever part I'm quilting is always on my left so I don't have it rolled up under the machine.
I am doing this now on a full quilt, so far so good.

I have heard from longarmers that some of them prefer the seam to be horizontal, because they usually roll and quilt vertically.

if you are quilting yourself- on a domestic machine vertical is fine- if you are sending your quilt to a long-arm quilter a horizontal seam is better- it lays nice and flat/smooth along the take up roller- instead of building up (4 layers at a time) in the center with every turn of the bar- which can cause saggy outside edges.

It depends on what is the simplest way to piece with the dimension of the top. I also throw in leftover fabrics on the back to save on having to buy too much fabric. I mostly do charity quilts and my budget is always tight.