If you’re looking at the 135x12mm size, chances are a small trim isn’t what the room needs. The 135mm face makes this Dressed MDF particularly worth considering for taller skirting or other areas where you want a broad, plain finish. Despite the extra width, it’s still only 12mm thick. There is no shaped face or decorative edge, either; the appeal is really in keeping the profile straightforward. Larger boards do need a little more planning. Measure along the walls and take note of doorways, built-in cabinets and other fixed details before ordering. It saves discovering an awkward junction once the work has started.