name may be known, the artist still may not be identifiable for certain; this is particularly 
difficult when several artists with the same last name worked for the Wiener Werkstätte 
simultaneously: Julius and Gustav Zimpel, Fritzi and Jakob Löw, Kitty and Felice Rix. And 
even though I had long been positive that the name “Knörlein" could only referto Rudolf 
Knörlein, in the case of KO-number 5839,1 ran across a certain “Frl. (Miss) Knörlein.” 
Information as to the individual years involved seems to be inconsistent, right from the 
beginning of the book; the numbers 5000 - 5003 and 5005 are labelled 1927; after 5005, 
there is a gap in the numeration, while the numbers 5140 - 6062 are relatively complete 
and their Sketches bear the annotation 1920 -1931. In most of the years listed, the date 
probably refers to the receipt, i.e., the sale and in only very few cases to the date of 
production (when it does not coincide with the first set of dates indicated above). 
Especially in the case of Commission goods (as for example with many ceramics 
designed by Vally Wieselthier), the production period maybeoneto several years prior 
to the date listed next to that particular number in the “KO-Buch”. 
Additional difficulties arise in the attempt to determine whetherthe “KO” ceramics were 
actually executed by, or merely designed by those artists listed (as for example in the 
case of Josef Hoffmann, Dagobert Peche, or Oskar Strnad among others, who were 
Abb. 7. Vally Wieselthier, Teil eines Kamins (KO-Nr. 5870, s.S. 273), um 1927; koloriertes Originalphoto 
aus dem Nachlaß der Wiener Werkstätte, Ausschnitt; bez.: “Nr. KO 5870, Design: Wieselthier, 40 x 59 cm, 
S. 1.200.-”. - Österreichisches Museum für angewandte Kunst 
27