# A question about hboxes and vboxes

I want to ask if is it possible (if such a process make sense) to print the hboxes and vboxes in order to gain a better understanding of the underfull/overfull hbox/vbox warnings. I use the showframe option of the geometry package but it prints just the bounding frame of each page .. thanks a lot .. Athanasios ...

• there is a luatex visual debug package – David Carlisle Oct 4 '17 at 15:02
• in addition to the luatex package, the usual command I add for any kind of debugging of output is \showoutput which puts a full representation of every box into the log – David Carlisle Oct 4 '17 at 15:06
• Every line of text is implemented as an \hbox (hence the overfull or underfull \hbox warning). Every column of text is implemented and a \vbox (using \unvbox to merge paragraphs and \vsplit at the end of the page). Every float is a savebox of some sort. Tabulars are full of \hbox and \vbox to align the rows and columns. I like to say that the TeX engine basically packs boxes inside other boxes. – John Kormylo Oct 7 '17 at 4:55