To use Guide Based Pagination guides must be created so that EasyCatalog knows where to paginate the items. EasyCatalog will detect where to place the first item by looking for a Guide Intersection, this is where a horizontal guide meets a vertical guide (see image below).
This is what a three column layout that paginates Down and Across would look like in terms of guide placement, when the pagination reaches the bottom of a column it will then search for the next guide intersection to place the next library item.
When paginating Across and Down a simple grid can be created if the product styles depth does not vary when populated, however if the product styles vary in depth create a layout like shown in the image below. When using a guide layout like this it will reduce the amount of space left between items when using ‘Use next position if item doesn’t fit’ in the ‘Paginate…’ dialog.