You can change the size of product pictures of your documents such as invoices, drafts, credit notes, packing slips, return forms, and quotes by following the simple steps below.
Also, changing the size of product pictures will change the size of documents’ PDF files.
Step 1: Open Simple Invoice from your Shopify store’s “Apps” section.
Step 2: Click on the “Templates” on the Simple Invoice dashboard.
Step 3: Scroll down to Product Images under Styling and select the image size from the Product image dropdown menu then click on the “Save” button.