Here I offer you two methods:
The first kind:
1. Find the original signature you want, preferably on blank paper. (Note: It should be made on clean white paper to achieve the function of simple post-processing! )
2. Scan the document with the original signature. Scan into the computer. (The resolution is higher, and it is recommended to be above 300dpi. )
3. Install photoshop, open the picture file with photoshop, click on the white background with the magic background eraser, and erase the white background. Then adjust the aspect ratio to your satisfaction, and then save it.
4. Download and install acrobat. After the installation, use acrobat to open the signed PDF document you need. Click File-Background-Add, then import the picture and adjust it with the view on the right. (The effect picture produced by this method is as follows: I added the picture to show the effect. )
5. output.
The second type:
1. Find the original signature you want, preferably on blank paper.
2. Scan the document with the original signature. Scan into the computer. (The resolution is higher, and it is recommended to be above 300dpi. )
3. Use photoshop to open the page of the PDF to be added, then make a merger, and finally directly synthesize the output.
Either method is ok, as for which one to use, you have the final say! I hope my method can help!