How do I identify a Loetz vase?

Rare, amazing hand-crafted 20th century Loetz Witwe vase from the Art Nouveau period in Bohemia (former Czech Republic) around 1915. This mesmerizing, so-called "Jack in the pulpit" ...

vase with drop applications, Johann Loetz Witwe, Capri decoration, ca. 1902 technique: glass, mouth-blown, reduced and iridescent

A fine quality Art Nouveau style art glass vase, by Loetz the historic glass maker from the municipality of Austria featuring Alvin Sterling Silver overlay. Overlay in form of open and horizontal patterns with stylized leaves and scrollwork. A great find, handcrafted vase skillfully made using centuries old techniques of art glass works from the world-renowned maker, Loetz. Simply stunning this Art Nouveau glass vase with Alvin Sterling Silver overlay by Loetz would enhance any shelf, table, nightstand or countertop. This is a rare antique Loetz Green Glass...

This antique Art Nouveau art glass vase by Michael Powolny for Loetz is an impressive and highly sought-after art piece from the early 20th cen...

Very beautiful German Art Déco hand blown glass vase (or high bowl) by Loetz Klostermühle Bohemia, 1930s. Orange to red, white, dark purple and clear glass with powder inclusions. ...

Loetz For Boudon And Klur Gilt Metal Monted Glass Vase. A highly sought after vase culminating the zenith of Loetz and the Art Nouveau design. Czech Republic Circa 1900 Rubin Ruby Papillon Decor Metal mount with indistinct impressed marks for Boudon and Klur Height: 10.5 Inches x 8 Inches wide x 5 Inches deep Condition: Very good with wear commensurate of age and use with some loss to gilt, The Loetz glassworks existed in Klostermuhle, Austria, for just over a hundred years, starting from 1840. But its heyday was during the life-time of Max Ritter Von Spaun, grandson of the original Johann Loetz who had founded the company. Von Spaun took over the company in 1879 and ran it until 1908, a year before his death. He was assisted by Eduard Prochaska, his technical specialist, and together they invented, designed and produced a whole series of wonderful new types of glass, taking out several patents and winning awards at all the major world exhibitions during the 1890's and the first years of the new century. The Loetz company were amongst the leaders in Art Nouveau design and expecially in irridescent art glass. "Papillon" glass, like the vase on the left, is sometimes known today as "oil spot" glass. Another favourite Loetz colouring was irridized glass with pulled trails called "Phenomenon" glass. There were irridized vases with ribbons of metallic colours winding over the surface, and many spectacular designs with applied trails of beautiful colours, or simply pulled out of the body of the glass to form handles or decoration. About 1900 the company started collaborating with outside designers, and some great artists designed pieces for Lotz, notably Joseph Hofmann, Koloman Moser, Maria Kirchner, and Hofstatter. In 1908 Loetz was taken over by Max Von Spaun's son, also called Max, and although it struggled financially (going through bankruptcy in 1911 and again in 1931) there were several great designers whose work was produced by Loetz during those years and through the art deco period. These included Adolf Beckert...