Sleeves are easy K. You can't let them moulder away in a drawer/cupboard, not after the beautiful job you did.
The standard size for Exhibition Quilts is 4" wide by 2" less than the width of the quilt.... But thats for the BIG quilts
What size lath are you going to hang them on?
I should imagine you wouldn't need anything too sturdy.
A trip to your local DIY or timber store will find you a length of something suitable.
Simple explanation of how to make a sleeve ... For
your size of Hanging .... 18" long x 14" wide.
Find a strip of wood about 1 1/2" wide x 1/4" thick and cut to your preferred length
Cut a rectangle of your backing fabric 14" x 5" .
Turn the short edges over by 1/2" twice, press and stitch down to make a neat edge
Your rectangle will measure something along the lines of 12" x 5" now.
Now fold the rectangle in half WRONG sides together
Stitch along the length to make a tube with the raw edged seam on the outside
Your sleeve will measure something like 12" x 4 - 4 1/2" now depending on your seam allowance
Open and press with the raw edged seam in the middle of the rectangle of fabric.
Turn so the raw edged seam lies against the back of the hanging
Position just below the binding and equidistant from each side of the hanging
Slip stitch along the top, bottom layer of the sides and bottom of the sleeve
Blimey!!!
that sounds awfully clunky when written down, but it really is very straightforward to do.
and there will be lots of tuts on Youtube that make it much easier to understand!