In Drupal Commerce, you can use the following to print out a field in your node.tpl.php file:
<?php print render($content['product:field_NAME']); ?>
But how do you print a field only if it has content?
For a normal Drupal field you would use the following:
<?php if (isset ($node->field_NAME)): ?> <?php print $node->field_NAME['und']['safe_value'];?> <?php endif; ?>
But that doesn't work with a Drupal commerce field.
I would appreciate if someone could offer any pointers!