The Tugra is a fantastic calligraphic device. It was invented by Uthmani calligraphers to represent the seal of the Uthmani Sultan. However, it is now used for various sorts of calligraphic representations such as Quranic script, signatures, and logos.
In an article on the Tugra, I demonstrate how non-Arabs have contributed to the Arabic script, particularly in the refinement of the Thuluth calligraphic style and the invention of the Tugra by the Uthmani Turks. I also try to show the origins of the shape of the Turga and analyze its visual characteristics. Finally, I show the impact of the Tugra on the design of modern logos such as that used by Al-Jazerra and by Bahrain TV.
I try to include some goodies with my blog entries, and this article includes a vector-based drawing of a Tugra in Adobe Illustrator format and an example of its usage with Arabic type in a PDF file. Both files are freely available for download and experimentation.