I feel strongly that quilts need to be labeled. I took on the project of labeling the quilts my mother made, and the one's in her possession and have been making labels for 25 years. In the past I've written about my favorite hand stitch for making labels, here and here. I have done a couple of counted cross-stitch labels on 50th wedding anniversary quilts....but that is very time consuming. My new favorite way is to have a friends embroider them on her machine....like this:
Here is a label I made in 1989 using permanent pen;
Here's another ink label, I remember making this one with freezer paper behind the yellow fabric and ironing it well to make it permanent; it has been washed once;
Here I had looked at the back of a speaker's quilt and she had labeled hers with the pigma marker on the hanging sleeve. So if you are in a hurry and don't have a label yet this will let you know when you finished it. But eventually it will need to be replaced with an embroidered one.
Then I went through a stage where I made labels using my sewing machine;
Now I usually frame the label like the one on top of this post or like this one;
Once I incorporated the label as part of the back of the quilt before it was quilted like this;
Finally another way I labeled a quilt that was not very successful. I painted it. White acrylic paint on a blue background..
Clearly labels need to be made with care and with a method that will hold up over time. Ink and paint is out. Embroidery is much better. Take the time to make a label that will last.