Digital signature field

In DC I no longer find the Digital Signature field.

I am creating a form for a client who wants to capture a Digital Signature.

On the Prepare Form toolbar there is "Add a Signature" and "Add a signature Block". I've used these and defined the field as "signature" but when I open the form in Reader, the field just accepts plain text. I've used digital signature field before and it always shows up with the red marker in the field.

Is this option no longer in DC or am I missing something?

Thanks

Brian