How to add watermark in each page for Salesforce visualforce pdf page?

Hi Pranav,

You will insert

<apex:page renderAs=""pdf"" standardStylesheets=""false"" applyHtmlTag=""false"" showHeader=""false"">

to top of the page.After that you will inert style inside the page.

<style>
@page {

background-image: url('https://login.salesforce.com/img/logo198.png');
background-repeat: no-repeat;
background-position: center;

}

</style>
Thanks.