Some 'Early Loetz Rainbow' Vases.

The first time Loetz 'Rainbow' décor was mentioned 1890 in 'Ackermann's Illustrierte Wiener Gewerbezeitschrift' and later again in 'Sprechsaal, 24 (1891) page 64' on the occasion of the 1890 exhibition of the 'Vienna Arts and Crafts Association'. Rainbow glass is mentioned only twice in production number PN=89 LB/4 and 89 LB /5 (1890, L. Boutigny, Paris) and then 37 years later in PN=III/3674 (1927) as 'Rainbow with crystal elephants' foot. The reason for this long gap may lay in the preference of the similar Loetz décor 'Tricolor' introduced in 1900. The 'Early Loetz' rainbow décor consists out of red, yellow, blue and brown (possibly: Rosalin, Topas, Saphir and Maron) clear glass splashes applied inside of crystal clear glass vessels. The clear glass is strongly UV reactive by its high Uranium content. The brown glass is especially responsible for the fine dark lines you can easily see in all vessels by using the CW picture enlargement mode. The tall vase in photo 2 has PN=I/1582 (1890), the PN's of the other vases remain unknown. The three vases in photo 1 are diagonal optically ribbed blown from top, have all the same type of handles and are known, too, in a rainbow-like red, blue and clear glass décor over white opal glass, blown in a optically finer ribbed shape and produced in later years, but as far as I know, never mentioned by any PN. As the name of the later opal glass décor is unknown, 'Rainbow' might therefore be restricted to the early crystal clear glass version only.
The tall vase of photo 2 is H=26.5 D=13x13 cm, the bowl of photo 3 is H=16.5 D=26x16.5 cm, the vase with the crimped rim in photo 4 is H=13.5 D=18x19 cm and finally the small vase exhibiting a fine persian décor is H=16 D=10 cm.