Conditional Formatting in Report if Text Field is Blank

[Lkrsfan2282]

I have attempted to apply conditional formatting to a text field in a report. The field either has info or is blank. I have tried applying a yellow background using and expression with the [field] Is Null. It does not appear to work in Print Preview but If I go into Report View and click on a field that is blank the cell background changes to yellow. When I click off the field the background returns to original state. Thanks in advance for your help with this.

[June7]

Is the BackColor property of the textbox set to Transparent?