The "Long text and summary" field has a pretty handy formatter called "Summary or trimmed". This will display a summary, if one is supplied, or Drupal will simply trim the text and display it.

The problem with this formatter is that you can't trim the summary. For example, if an editor adds three paragraphs into the summary section, then the whole summary is shown. But sometimes you may need control over how much of the summary is displayed. This is especially true if your design requires the teaser to have a consistent height.

What's the best way of offering a summary to your editors that also trims it? Enter Smart Trim.

The Smart Trim module is an improved version of the "Summary or Trimmed" formatter and a whole lot more. It does a lot of useful stuff, but the one we want to discuss is the ability to trim summaries.