Zwiebelmuster Cup + Saucer 0.30L + 17.5cm, Original Bohemia Blue Onion Pattern from Dubi
2nd Quality!

Cup: Volume: 0.30L, Height: 6cm, Diameter: 13cm, Weight: 250g
Saucer: Height: 3cm, Diameter: 17.5cm, Weight: 230g

Painting (Onion Pattern) is under the glaze which makes the product safe to use in microwave and dishwasher. Breaking the product with a force is the only way how to interrupt painting.
(Glaze is thin, clear, and protective material applied to ceramics)

Second choice:
2. Quality
The second quality is the same utility and health characteristics as the 1st quality. http://www.zwiebelmuster.eu/zertifikat/ .You differs only inaccuracies in the painting and sometimes by two or three blue or brown spots or stains. In the ordinary benefits these inaccuracies are almost imperceptible. The product of the second quality is recognized by a scribe on the trade mark, which is placed on the lower part of the product and on the label of the original packing (sometimes you can palpate only with your finger or nail). The second quality is usually cheaper by 20%. If you have questions, contact us at: jankla@zwiebelmuster.cz

The product is very safe to use - more at http://www.zwiebelmuster.eu/zertifikat-zwiebelmuster/
In Czech Republic, There are many producers of Blue Onion Pattern, but only Bohemia Blue Pattern from Dubi this trademark:

 
 
The trademark has been modified over the years. More you can find here: http://www.zwiebelmuster.eu/geschichte/