from skylineAppendix:

To understand the letterforms of a particular language, it is necessary to know the characteristics of the material it was written on. We noted above, for instance, the difference between the letterforms carved on the Rosetta Stone and the uncial script of the same general period: The engraved letterforms use almost entirely straight strokes.

Nonetheless it is clear that the Greek alphabet is originally a written (as opposed to a carved or inscribed) alphabet. This is in contrast to, for instance, the German runic alphabet, designed for inscriptions; its every stroke is straight.

Even more curious are the letterforms used in the Indian Ocean region (Sri Lanki, Burma). Books in those areas were written on palm leaves which had been cut to size and smoothed. Letters were inscribed with a stylus, and then (in at least some cases) inked.

Because the palm leaves were fragile and had a distinct grain, it was not possible, in the case of these writings, to use a horizontal stroke. Such a stroke would inevitably split the grain of the palm leaf, ruining the writing surface.

I have read that portions of the Quran were written on palm leaves also. But these portions were actually written, not inscribed, so the matter of stroke directions is somewhat less significant.

Other odd writing materials would have other effects. Certain important classical documents, e.g., were written on linen or woven cloth. Such cloth may not have a grain, but if it does, it will usually be easier to write horizontal and vertical strokes. And curves would be difficult on any woven material.

Cuneiform writing was not restricted so much by the writing material (clay will accept strokes in any direction) as by the stylus used to write it. You could, theoretically, draw almost anything in such a system, but it will be much slower.

All of these constraints have affected writing at one time or another. Imagine trying to inscribe the myriad symbols of Chinese writing in stone! The Chinese ideographic alphabet is possible only on surfaces which make writing possible. Surfaces which make writing difficult but make different strokes possible, on the other hand, encourage syllabaries, which use fewer strokes than alphabetic systems though they are somewhat harder to learn.

These concerns are not entirely trivial for students of New Testament writing and paleography. Papyrus was not as fragile as palm leaf, but it did have a very definite grain. This seems to be one reason why the codex was not popular for classical writings. A papyrus sheet consisted of two sets of strips pasted together. For reasons of strength, one set of strips would be set vertically, the other horizontally – as a toy house today might be made with a double set of popsicle sticks, one half running vertically, the other horizontally. It was easy enough to write on the horizontal side – indeed, that side of the sheet would not even need to be ruled. The vertical side was another matter. There were, of course, seams between the reeds of the vertical side; writing on these seams was difficult, but avoiding them was also problematic.

The roughness of the papyrus also had the effect of encouraging straight strokes. This was much less of a concern on vellum, which was nearly smooth and did not hinder curved strokes.

Peyami Gurel was born in 1959, Istanbul. After he completed his economy education, he made researches on art and philosophy at different universities in Germany, Austria, and Switzerland. Beginning from his grown up ages, he has been interested in history of art, philosophy, and social sciences. As a result, he published several articles about art and aesthetics.The artist established and directed an art gallery in 1993. In addition to his paintings, he is closely interested in different branches of traditional arts such as marbling (ebru) and calligraphy. In the years between 1996-1997, he prepared and presented a TV program which was a live broadcast weekly in order to endear traditional and modern arts to society. He owns a special multimedia and graphic design company. His unique works of art are now existing in worldwide private individual and institutional collections. The artist has worked as an art director and as an advisor in many goverment releated and private companies.

Peyami Gurel is an artist who made technical researches in traditional arts and added new expansions on them with modern attitude; (marbling, calligraphy and miniature)He continues to paint in his workshop in Istanbul and educate his students by giving a special importance in the field of traditional arts while spreading his other hand to future and modernism. Throughout his career, making rare personal exhibitions is a principle he kept, likely he attended few mixed exhibitions. His art expression is related to ontological and existentialist dimensions . His main problematic is existance and his attributions are for the pure sole. (well beloved) The artist is deeply affected by hermetic teaching and mysticism . He continues to paint with a modern attitude.

from here