There are a lot of things to think about before bringing your quilt in for longarm quilting, but I'll try to make this quick and painless.
Please make sure your backing is at least 6" wider and longer than your quilt top. This allows me at least 3" on each side of your quilt.
After you've pieced your backing, trimming your selvages and pressing your seams open will help get the backing smooth.
If possible, Horizontal seams are always best and will lay flat. While vertical seams could potentially cause minor distortion in the backing.
Backing must be square. Meaning, your top and bottom edges really need to be straight, without jagged edges. I recommend rotary cutting. If the selvage edges are at top and bottom, this is great!
Straight edges are imperative when loading the quilt onto the longarm. If your edges are not straight, this can cause rippling or pleats in the backing that cannot always be worked out during quilting and will quite possibly go unseen until the quilt is finished.
Try not to make your backing "fit" your quilt top. Such as pieced backings, borders, blocks, etc. It is very difficult to center (side to side) a quilt top to the backing and almost impossible to center the top and bottom as we quilt with the view of the quilt top, not the backing (without crawling on the floor that is).
Here is a great, quick video by Fat Quarter Shop for preparing your quilt for a longarmer.
I will often have some batting options available, if I do not have what you want in stock, I can buy or order it. This may add a few days to turnaround time, but we can discuss options. (I do not currently use large rolls of batting stored on my machine. All batting available will be pre-packaged.)
If you provide your own batting, please be sure it is larger than your quilt top. It's okay to have batting that is larger than your project.
BORDERS WITH HEAVY PIECING -
If you have piece work around the sides of your quilt top, it may help to sew along edge to "stay stitch" to ensure your piecing stays in tact. 1/8" from edge is perfect and will be covered by the binding when finished.
MAKING SURE BORDERS ARE FLAT -
Sewing your borders correctly will make a huge difference in the final look of your quilt after quilting is finished.
Check out this video for adding borders and making sure your borders lay flat.
Save the extras for later. Any buttons, etc will need to be saved for later or removed for quilting and reattached. We don't want to risk hitting a button during quilting and break either a machine needle, button or tearing your quilt.
I hope that all of these tips I have found helpful, help you as well. I feel like anything else that comes up, we can discuss case by case.
Can't wait to get started on your quilt!
*I also quilt foam interfacing for bag projects, classes etc. I often use my long arm for quilting my own foam interfacing for numerous projects.