Invoices for Salesforce automatically creates an invoice record and invoice PDF for each sale, straight out of the sales's opportunity record, and according to the template assigned to it. So your invoice templates define the blueprints for:
You can create invoice templates in one of three ways. You can create a new template based on a predefined template, you can clone one of your existing templates to reuse its design, or you can create a new template from scratch. The predefined templates are part of a gallery of ready made samples from which you can choose and use it as it is, or modify it to your needs.
The invoice template creation and editing interface is a wizard with two or three steps, depending on whether you are creating or editing a template, and depending on whether you choose to create a new one using a predefined sample or starting your design from scratch. In all cases however, the wizard always leads you to the "Invoice layout and content" page which contains the invoice template editor. The editor displays a representation of a paper copy of the invoice PDF placed on a desk, following the desktop metaphor, with a toolbox that let you select, edit, and add different type of elements to the invoice page. The type of elements you can add to the page include:
These elements are the building blocks of your invoice design. As you add elements to the page, you can resize, move, and position them to compose the blueprint of your invoice content and layout.
Each one of the elements type has its own editor that you use to add its content, and define its display style such as font color, type, weight, and more. The textual content of the Text and Summary Table types can also include dynamic data from your sales records. Their editor include a list of available fields from the sales objects you can add to the element's content in the form of merge fields. When the invoices are created, these merge fields are replaced with data from your records that correspond to the field. The invoice items table, on the other hand, displays data from your products records. So the Invoice Items Table editor displays the list of available fields from the products objects that can be included in each of the table columns.
With Invoices for Salesforce you do not need to mantain the customization of the Invoice and Invoice Line Item objects used to capture the invoice records automatically created along with the invoice PDF. This is because Invoices for Salesforce uses the merge fields in the invoice templates to automatically mantain the customization of these objects for you. (This only applies to Enterprise, Unlimited, and Developer Editions of Salesforce. Professional Edition users need to customize these objects manually as described here). The way this works is as follows. Every time you save a new or an existing template, Invoices for Salesforce collects all the new merge fields, and in the backgroud creates a new field for each in the invoice objects, using the same type of the field in the merge field expression. The idea is that you think about invoices in term of invoice PDF document, and the application takes care of the rest. So the invoice template also defines the blueprint of the invoice objects records, in addition to defining the blueprint of the invoice PDF documents.
The dynamic data in your invoice templates depend on the standard and custom fields from your sales and product objects you add to your templates. Consequently you must be careful when changing the customization of these objects in that the changes you make do not have an impact on your invoice templates. Invoices for Salesforce checks before billing and before creating new templates or editing existing ones that any customization changes you made to your sales and product objects do not affect your invoice templates. In the event that you made changes that have an effect on your invoice templates, the application warns you and points you out to the changes you made that need to be reverted to proceed as described in Invoice Templates Integrity.
The invoice template editor includes a preview button you can use at any stage of your template editing to create a PDF version of your template, to see your design in its final format.