This guide will cover only the 1848/1849 Hohenzollern Denkmünze ribbon (both für Kämpfer & für Nicht-Kämpfer).  The medals are covered in the guides http://reviews.ebay.com/1848-1849-Hohenzollern-Denkmuenze-fuer-Kaempfer_W0QQugidZ10000000003623774 and http://reviews.ebay.com/1848-1849-Hohenzollern-Denkmuenze-fuer-Nicht-Kaempfer_W0QQugidZ10000000003612920.  The 1848/1849 Hohenzollern Denkmünze was established on 23 August 1851 by King Friedrich Wilhelm IV of Prussia, along with the Hohenzollern House Order. 

1848/1849 Hohenzollern Denkmünze ribbon 

The original issue ribbon was made in Berlin.   The silk ribbon (UV-negative) is almost 3.5cm wide and is the color of the civil Iron Cross with an additional thin central black stripe.  The various ribbon types have notes which are of interest to the collector: 

• Contemporary Ribbon:  Silk, the weave is 16-17 rows per cm, each thread is 2 strands of ca. 10-12 fibers per strand, and it is UV-negative.  The original issue ribbon was 3.50cm wide.  A wavy weft is typically very noticable.
• WWI-era Ribbon:  Silk, the weave is 15 rows per cm, each thread is 2 strands of ca. 20 fibers per strand, and it is UV-negative.  Silk, the weave is 16 rows per cm, each thread is 2 strands of ca. 15 fibers per strand, and it is UV-negative. 
• WWII-era Ribbon: Silk, the weave is 15 rows per cm, each thread is 2 strands of ca. 15 fibers per strand, and it is UV-negative.  Cotton, the weave is 14 rows per cm, each thread is 2 strands of ca. 10-12 fibers per strand, and it is UV-negative.
• Modern-era Ribbon: Often found in widths of exactly 2.90cm, 2.95cm, 3.00cm, 3.05cm, 3.10cm, 3.15, or 3.20cm.  Silk, the weave is 14 rows per cm, each thread is 3 strands of ca. 10 fibers per strand, and it is UV-negative.  Cotton, the weave is 13 rows per cm, each thread is 2 strands of ca. 15 fibers per strand, and it is UV-negative.  Poly, the thread melts and clumps when burned, the weave is 15 rows per cm, each thread is 2 strands of ca. 10 fibers per strand, and it is UV-positive.  Cotton, the weave is 14 rows per cm, and each thread is 3 strands of ca. 8-10 fibers per strand.  Note that some of these ribbons have a false UV-positive due to the use of a fabric finish. Poly-cotton mix, the weave is 14-15 rows per cm, each thread is 2 strands of ca. 10-15 fibers per strand, and it is UV-positive.  It's important to note that many of the modern-era ribbons are made in such a fashion that the white fibers can often be seen through the black weave. 

My best advice is:  Buy only from a reputable dealer who specializes in Prussian or Imperial German medals.  Please visit my blog (http://blogs.ebay.com/tsa-li) and/or guides (http://reviews.ebay.com/Hohenzollern-Medal-Guide-Index_W0QQugidZ10000000003443079) for further information.  Thank you for your visit!