The “Tube Script” is an individual handwriting with a somewhat “wet” character. The pen was a tube full of color. It is easy to understand that this is not really a nice way to write. Sometimes the line is very thin and delicate, other times it’s just a fat blob that’s supposed to represent a letter, depending on how hard the tube was pressed. This creates organic forms, random effects, breaks, and smears, where normally the writer determines the form.