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The PDF files are also generated from Smarty templates (.tpl files). The main difference with the template files used to generate HTML, is that the PDF templates do not allow for external resources such as CSS. Therefore you must use internal or inline styling in order to change the style of your invoice, order slip, return slip, etc. A default PrestaShop installation comes with two style templates: delivery-slip.style-tab.tpl and invoice.style-tab.tpl. You can find these in the folder /pdf/. The following table shows how the style tabs are linked:
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Note that if you would like to apply a different style template, you will have to override the corresponding PDF Class in the directory /classes/pdf/.
The internal styling in the style tabs can only be applied to the main PDF template files, such as invoice.tpl, delivery-slip.tpl, etc. In order to reuse the variables in this template in templates which are included, you can assign Smarty variables or apply inline styling separately in each of these files.
Scratching that itch: creating all files from zero
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