Since V1.1.2 the setup to connect Gravity Form with Fancy Product Designer has changed.
Open the field options and click on the "Appearance" tab and enter "fpd-order" in the Custom CSS class input.
Last but not least go to the Advanced tab and enable "Hidden" show this field is not showing up in the form.
Since version 1.1.0 of the PLUS add-on for Fancy Product Designer you can connect Gravity Form with the product designer.
Go to the Form Settings of a form and scroll to the Form Options section, there you will find an option to connect the selected form with Fancy Product Designer.
Now create a post or page and insert the Gravity Form and use following shortcode to display the product designer in any specific position in your page:
You can view the customized product that was sent via a Gravity Form in the entries of Gravity Form admin.