The large 4' x 4' dry erase line graph boards are an interesting alternative to the popular XY axis grid boards because you get a blow up of only one quadrant vs. a print of all four quadrants. There is a bold axis line on the left that intersects with another axis line that crosses the bottom. There is a 1" x 1" grid where every fifth line is a little darker or bolder to make your graph easier to follow and plot or read. The 1" x 1" grid gives you a total of 40 rows and 40 columns in total. The print is covered in our exclusive clear dry erase writing surface so it's protected for the life of the board which under proper care will last for years to come. You have the option of a magnetic or a non-magnetic version. The magnetic version is a little more expensive but it gives you the option of using magnetic accessories with your line graph. Both versions are made in the U.S.A. and we gladly accept school purchase orders. We can also modify any print to your specifications for a small artwork fee.