If you have ever written a journal article or thesis using LaTeX then you probably came across lots of errors and warnings in the process. Those warnings can usually be ignored as they don’t stop the document from compiling, and many of us who just want to cross the finishing line probably never investigate what was causing them.
One such common warning is the Overfull or Underfull /hbox message.
These usually occur through no fault of the author, but because LaTeX doesn’t know how to hy-ph-enate certain words. You see, LaTeX tries to typeset in a strict column width and has a dictionary of words that includes hyphenation information that tells it where the most logical places to split a word up are, with some order of priority. When it wants to flow text at the end of a line it can and does automatically hyphenate (usually longer) words to keep the character spacing constant while adhering to the strict column width.
What I have found is that certain words I was using were not in the LaTeX list of words and the /hbox problems were caused by LaTeX not knowing how to hyphenate them. Thus the column widths were being messed up. Such special words for me were micromagnetics, intergranular and so on.
By supplying forced hyphenation marks manually, e.g. micro\-mag\-net\-ics I was able to get rid of all the warnings.