My first look at a cross-written letters was a photograph plate in a biography of the author George MacDonald. Before this, I did not know that cross-writing existed, nor had ever seen a piece of writing or a letter that was cross-written. From this it can be inferred that I had never paid a lot of attention to Jane Austen who often cross-wrote her many letters in order to save on postage.

Austen's cross-writing is at ninety degrees, and I find it really a strain on the eyes to puzzle it out. The family of MacDonalds, a number of whose letters are quoted, and some photographed, in Rolland Hain's "Victorian Mythmaker" biography, preferred forty-five degrees to ninety degrees, judging from the photos. It is easier to read the forty-five degree cross-writing, there is something about the diagonal slant that is more quickly understood by the eye.

What is your acquaintance / experience with cross-written documents?