There is no limit to how many products can be displayed on your DHL Commercial invoices;
Although the product cap is around 8 products per page, Shiptheory supports multiple customs pages where required, meaning that your products will flow onto the next page. Just ensure you have sufficient paper in your printer if printing an order with a large quantity of products.
If you have any issues with this, such as orders not printing as they should, please reach out to support.