We use the built in WooCommerce email template system. You can find out more about customization here: https://docs.woocommerce.com/document/configuring-woocommerce-settings/#section-23
To override the email you should copy these two files:
/wp-content/plugins/pw-woocommerce-gift-cards/templates/woocommerce/emails/customer-pw-gift-card.php
/wp-content/plugins/pw-woocommerce-gift-cards/templates/woocommerce/emails/plain/customer-pw-gift-card.php
To here:
/wp-content/themes/<your_theme>/woocommerce/emails/customer-pw-gift-card.php
/wp-content/themes/<your_theme>/woocommerce/emails/plain/customer-pw-gift-card.php
Once the files are in your theme folder, open them up in a text editor and make any changes.
As for printable cards, the purchaser should put their own email address in the ‘To’ field. That way they will get the email and can print it out instead of having it delivered electronically to the recipient. You can add these instructions to the Product Description for the PW Gift Card product.
We have a feature on our software development roadmap to allow you to specify different stock images for things such as birthdays, anniversaries, etc. Additionally, the customer could upload their own image. We don’t have an ETA on this right now though, however if you would like I can notify you here when it’s available.