Don't bother. Laminated charts are bulkier & harder to fold because of the stiffness. Use a soft - but not too soft - pencil & a good rubber/eraser to remove it. 2B is my preference. It's soft enough to be erased easily without damaging the chart and hard enough not to need sharpening too often. Not covering/laminating also means that you don't require a special marker just for writing on your map so if you drop or lose your writing stick anything handy can be used. My maps lasted years that way.
If you must cover your charts, see if you can find clear contact with a slightly roughened, matte surface instead of the typical smooth glossy stuff. Alternatively you can use very fine sandpaper to lightly buff the surface of the glossy stuff. A soft pencil or even a pen can then be used to write on it.
Last edited by Tinstaafl; 11th May 2010 at 01:33.