When you're working with the collection tag and want to use paginationopen in new window, just add the pagination partial using partial:components/pagination to automagically add pagination buttons. They're easily editable in resources/views/components/_pagination.antlers.html.

The pagination partial automatically adds linktags to your documents head with rel="next" and rel="prev".

Note: the strings used in the partial are translatable and can be edited in resources/lang/en/site.php.