Cropping is a universal functionality that all image viewing software, such as Preview on Mac or Photo Viewer on Windows. Pro Tip: If you need to resize or crop the scanned signature that had been inserted into your Word document, use your local image reader to crop it. You can then easily drag and drop the image file into your Word document, or click Insert > Pictures > Picture from File. Scan your signature with a scanner and export it to your computer.

To insert a handwritten signature to your Word document, follow the steps below: How to Insert Signature in Word - from Scanned Files

Instead, here are a few ways to insert a signature in Word documents. However, you cannot create a signature directly from Microsoft Word. Electronic signatures, especially handwritten ones are great to personalize your content. This ranges from cover letters, newsletters, contracts. Many documents that are created with the standard text editor - Microsoft Word requires a signature.