5509 is an embroidery linen by Libeco, the Belgian linen weaver founded in 1858: the even weave makes the threads easy to count, and the stiffened finish ("embroidery stiffened") keeps the fabric firm and taut while you stitch. It is made for cross stitch and all counted thread embroidery: pictures and samplers, place mats, table centres and household linen.
Cross stitch over two threads gives about 17 stitches per inch (6.7 per cm): work with one or two strands of stranded cotton, depending on the coverage you want. Leave a generous margin around the design for framing or for hems and finishing.