For instance on the list page you need to display first 80 characters but on the print page you need to limit it to 500 characters.
- On Miscellaneous screen under 'Truncate large text fields' enter 80
- Under View as/Edit as settings of this field choose 'Different settings for each page' option. On Printer page choose View as type 'Custom'.
It will display the whole content of the field. If you need to restrict it to 500 characters add the following code there:
$value = substr($value , 0, 500);