How to change PDF Invoice Logo, shipment logo in Magento 2

1. On the Admin sidebar, click Stores > Settings > Configuration. Then, look into the panel on the left, under Sales, click on Sales
2. Open the Invoice and Packing Slip Design section. Then, do the following:

• To upload the Logo for PDF Print-outs, click Choose File. Choose the logo, then click Open
• To upload the Logo for HTML Print View, click Choose File. Choose the logo, then click Open
• Fill your address to show on invoices and packing slips.

1. When complete, click Save Config. Note: The ratio of the logo will be correct on the invoice even on case of the thumbnail appears distorted.

Replacing an image

1. Click Choose File and select other logo file as you want.
2. Mark the Delete Image checkbox for the image you want to replace.
3. Click Save Config.