How do I add pagination for a custom page listing custom post types?

    <section class="blog-main-content">
        <h2>Blog</h2>
        <?php $paged = ( get_query_var( 'paged' ) ) ? get_query_var( 'paged' ) : 1; ?>

        <?php $loop = new WP_Query( array( 'post_type' => array('blog', 'post'), 'posts_per_page' => '4', '&paged' => $paged ) ); ?>

        <?php if ( $loop->have_posts() ) : while ( $loop->have_posts() ) : $loop->the_post(); ?>

            <div class="blog-individual-post">
                <a href="<?php the_permalink(); ?>"><h2><?php the_title(); ?></h2></a>

                <section class="blog-individual-date-and-author">
                    <?php the_time('F jS, Y'); ?> by <em><?php the_author_posts_link(); ?></em>
                </section>

                <section class="blog-numbered-comments">
                    This post currently has
                    <a href="<?php comments_link();?>"><strong><?php comments_number( 'no comments', '1 comment', '% comments' ); ?></strong></a>
                </section>

                <div class="blog-entry">
                    <?php the_content(); ?>
                </div>
            </div>
        <?php endwhile; endif; ?>

        <?php

            // next_posts_link() usage with max_num_pages
            next_posts_link( 'Older Entries', $loop->max_num_pages );
            previous_posts_link( 'Newer Entries' );
        ?>

    </section>

</section>