Bootstrap 3 – Print layout and breaks after each grid column

Bojangles comment got me in the right direction, so I’ll answer my own question.

Using the ‘xs’ size grid columns, which according to http://getbootstrap.com/css/#grid-options is for “Extra small devices Phones (<768px)”, Bootstrap happily prints as expected.

<div class="container">
  <div class="row">
    <div class="col-xs-6">Column1</div>
    <div class="col-xs-6">Column2</div>
  </div>
</div>