Here are Valentines handkerchiefs from my collection.
The middle 20th c was quite nostalgic. You see a lot of hoop skirt/top hat couples.
This is a great example of handkerchief design in its hey-day.
Machine embroidered handkerchiefs were cheap gifts in the later 20th c.
And a small quilt hanging I made based on a vintage Valentine card and using handkerchiefs in the border. The pattern is available at my etsy shop Rosemont Needle Arts.