These printed cloth gaming mats have been manufactured by Geek Villain for gaming with To the Strongest! The mats are made from a high-quality durable fleece. The material used has a grassy "texture" on both sides, and has a degree of stretch to it, which allows books or similar to be placed beneath it to make hills. The grass and stones design is perfect for many parts of Europe, Asia and North America.
The mats are a minimum of 6' by 4' (1800mm x 1200mm) in size, but are deliberately cut somewhat oversized, usually around 76" by 56", so as to hang over the edges of a typical 6' x 4' gaming table.
The mats come either plain, or printed with an unobtrusive 15cm cross-grid (i.e. not solid grid lines, but a faint cross at the intersection of the grid lines). This grid size is typically used with 28mm or 20mm minis, or larger units of 15mm miniatures.
You can find the mats here. I regularly post overseas.