Order
In order for comic strip and graphic novel dialogue to make sense, it has to be read in order. Thus, conventions have evolved in the order in which the communication bubbles are read. The individual bubbles are read in the order of the language. For example, in English, the bubbles are read from left to right in a panel, while in Japanese, it is the other way around. Sometimes the bubbles are "stacked", with two characters having multiple bubbles, one above the other. Such stacks are read from the top down. Poor use of speech balloons can unintentionally make the proper reading order ambiguous, confusing the reader.