Reticello is another one of my fascinations... I really like the chiaroscuro of the filled and unfilled areas. I'm always drawn to it and have many books on the subject. My own attempts have been relatively successful though no where near the perfection of true Italian masters.
Handkerchiefs are a nice way to collect samples of different techniques, if you can find them reasonably priced in antiques markets. I am stunned by the amount of work that has gone into artifacts which are so small. You need really fine thread to work these, good eyesight and lots of patience!
In October of 1987 the Palazzo Davanzati in Florence published a catalogue of some of its collection of laces and embroideries which had been donated by various Italian collectors. In this catalogue is a section on the collection of mostly handkerchiefs donated to the museum in 1986 by the Duchess Franca di Grazzano Visconti di Modrone (1905 - 2003).
This one is still on display in a drawer while many of the others are stored away:
The catalogue information says that it is made of Batiste and embroidered in Reticello and Rodi Stitch (inside the bigger leaves), Padded Satin Stitch, Tailor's Buttonhole Stitch and "Cordonetto" (I don't know what that is referring to) finished around the edge with needle lace. It measures 37 x 37 cm and all the corners are rounded and in one, above the motif, sits the coat of arms of the Viviani della Robbia family, the Duchess's maiden name, topped with a marquis crown. It is an excellent example of Drawn-thread work and Cutwork and is dated the first quarter of the 20th century.
The square Reticello motifs are worked into the fabric, not inserted - can you even think about working Cutwork and Drawn-Thread work on this fine of fabric?! I'm sorry my photos are a bit blurry, I was leaning overtop of the open drawer which was at shin-level.
Though all the catalogue photos are black and white, there are many, many fine examples of embroidered and lace-worked handkerchiefs with their relative information (in Italian). The section on the Duchess's handkerchiefs is one of three; the others are Lace and Embroideries from the 18th and 19th centuries and Lace and Embroidered Baptismal and Newborn artifacts which includes an exquisite collection of bonnets. The catalogue can be found in used bookstores online, it is called: Eleganza e civetterie: merletti e ricami a Palazzo Davanzati, 1987, Marina Carmignani.
If you are looking for a book on handkerchiefs with a more Italian flavour, The Handkerchief by Paolo Peri, 1992, is in English and has mostly Italian examples with particular attention to the 20th century. It has lots of good historical information, there are many colour photos and examples of handkerchiefs in art.
In the "History" section of Tuttoricamo's website there is an excellent article called: Handkerchief, a protagonist in decline. There are also two great how-to articles on Reticello in the "How its done" section.