Sample Envelope of Dennison's Gummed Suspension Rings for Printers

[Framingham, Massachusetts]: [Dennison Mfg. Co.], 1870. Very good. Toned. Sealed, with samples not able to be inspected for condition.. An envelope enclosing samples of "Dennison's Gummed Suspension Rings", marketed as tough paper tabs for printers (perhaps to hang wet prints): "Printers will find these single RINGS more convenient and cheaper than eyelets". The envelope illustrated the different tabs available, each with an order number and price. The envelope remains sealed as issued, put appears to indeed contain the original sample, or samples, inside. Measures approx. 5.5" by 3