When you want to target the customers who are very busy it becomes necessary that you highlight every word in every line that is important for the customer to view. Also, changing the format is easy if it is just for one customer. What about the situation when such extensive format changes have to be done for each customer. For example, the discount that a person could get could have a common color but the rewards point could be different from one customer to another. Also, the discount if any on purchase amount should be made clear and also this information should be clearly displayed for every upper and lower limit of the billing that is done by the customer.
This sort of formatting the content by size, font family and color is tough unless you use the URL to PDF conversion API in which you could make use of the CSS to make the format changes as simple as possible. How to include the CSS is very clearly given online which you could follow as is so as to see the exact impact of using CSS on the PDF files that would be rendered to the end users. Do not hesitate to ask questions to the support team that would be operating round the clock. Of course the support would be rendered to you on several topics but would depend on the package you have chosen to render the images and content to end users.
You could see that along with the support, certain custom features would be enabled for you depending on the investment you do on availing the packages that are made available by these APIs. Try to be economical in availing these packages and effectively reach out to the customers.