app/views/layouts/pdf.html.erb
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<%= wicked_pdf_stylesheet_link_tag "pdf" -%>
</head>
<body>
<div id="content">
<%= yield %>
</div>
</body>
</html>