How is Hebrew similar to Arabic?

Handwriting: How did pre-modern Arabic and Hebrew writers keep from smudging their writing?

• Old Japanese and Chinese were written with a pointed brush held nearly vertically, top to bottom and right to left, which kept the writing from smudging. Lefties in European languages which go from left to write smudge a lot unless they adopt some hacks. What do Arabic and Hebrew writers do? What made it plausible and possible to write from right to left?

• Answer:

  Hebrew writers do smudge their hands or hold their pens carefully to position their hands below the text. I assume Arabic scribes use similar positions. The expert scribes are very careful and produce beautiful scripts that look artistic even if you cannot read them. Regular people who write in these languages simply adopt a pen hold that avoids the smudges much like left-handed people write in European languages by holding the pen, or bending the wrist above or below the text to avoid the smudge. Now, for the related question -- why did these language start right to left, when it seems much easier to prevent smudges if you write left to right.  My theory is that the language originated as a carved language -- thus you'd use hammer and chisel.  . It's easier to chisel when you start from the right and move to the left. Once the languages of the Levant, such as Hebrew, Arabic and others became scribed, not carved -- they adopted wavy, curvy letters. But they did not adopt the left to right direction. (I'm not sure why.) Whereas languages that started off as ink on paper/papyrus probably started off left to right in the first place. Does this make sense? I think so, but if you know this to be true or false, let me know, since I've always been puzzled by this too.