Creating fillable fields in a PDF.

Creating fillable fields in a PDF.
Can anyone help me with the following. I am in the process of building a fillable pdf form where the last page should have a large area to draw something like an outline sketch. I searched my ass off at the tools in Adobe Acrobat Pro but all I found was a section that allows you to add a signature. So it's really about being able to draw lines and put text in that large area. Who has a nice solution?