Hello,

Clay is already nearly there when it comes to supporting paged media, for use with @media print in browsers or dedicated typesetters such as Prince.

Many of the changes are simply adding combinators; a suitable Clay.Paged module might be suitable.

One change is more substantial. @page queries can take nested css, like @media queries. For example, the following displays the line "This page is intentionally left blank" at the top of any page which has the associated pseudo-selector blank.

@page :blank {
  @top-center { content: "This page is intentionally left blank." }
}

It looks like extending, replacing or complementing the query functions to handle more than just media queries would be the best way to go about implementing this. As it stands my workaround involves wrapping the @top-center { … } using a monster regular expression in vim.

It would be good to fully support the CSS paged media spec. How would this best be done?

See https://www.smashingmagazine.com/2015/01/designing-for-print-with-css/ for a good description of the capabilities.