Filter media packs that utilizes a zig-zag folding pattern on deeply corrugated filter media are described. The filter media is scored, folded, and secured into position to form the filter media pack. The filter media pack may be secured using a self-supporting structure (e.g., via tacking adhesive used to secure adjacent folds). The filter media pack contains unique features to optimize filtration performance, such as maximized inlet and outlet face flow areas. In some arrangements, the filter media pack exhibits improved flow characteristics and dust-holding capacity via upstream and downstream channels that have different cross-sectional shapes and/or sizes. The upstream and downstream channels may comprise, for example, circular, diamond shaped, or fish-scale shaped openings.