Thank you for your post!
You might see pre-made solution and plug-ins which might achieve this for you: Made for FileMaker
I'm also going to move this thread from the FileMaker Community Feedback Space (which is specifically for input on the Community itself) to the Discussions Space where you should receive more views and potentially more feedback on this topic!
Since you are using an iPAD, you have two basic options:
Use InsertDevice with the signature option.
Set up a web viewer with java scripting that converts the web viewer space into a sketch pad.
The simplest solution would be to use the built in signature capture option as suggested by philmodjunk, which could also be used for the basic drawing.
You would have two container fields, one for signature, one for drawing... and then maybe have a layout designed to be saved as PDF which includes all your order information fields as well as the drawing and signature. This PDF can then be emailed etc.
For a more complex solution, then using the Web Viewer to integrate an HTML5 canvas based sketch thingie such as GoDraw - FileMaker Drawing Tool - GoDraw v2.0 - Draw Arrows, Lines and Shapes - or FMEasyCanvas ( FMEasyCanvas | An Open Source Drawing Solution for the FileMaker Platform ) could work... I've recently adapted the latest version of 'Literally Canvas' - Literally Canvas — Literally Canvas v0.4.14 docs - HTML5 drawing board - MS Paint in your web browser - which FMEasyCanvas is based on, to work with a project that needed a lot of customisation....
Anyway, for an example of just using the built in signature capture, see attached file :-)
TreeService.fmp12.zip 185.2 K