Many CNC plasma cutting machines include a one-piece material support surface.  This can either be a welded gridwork made of vertical steel slats, or a number of supports dovetailed together into a support structure.
 
The disadvantage to these support surfaces is they must be replaced in their entirety when even a small part of the cutting surface becomes unusable.  Surfaces that support the material with points, rather than slats, tend to promote the tipping up of cut pieces, which can easily block the path of the torch.  Pointed surfaces also make it difficult to remove a plate with cutouts, as seen below, due to the points hanging up on the openings.
 
Work supports are sacrificial, in that they become destroyed by the plasma torch over time.  It is vital that you use a support structure made of individually replaceable steel slats.  That way, you spend only a few dollars to make the surface like new, rather than hundreds of dollars for a complete new support grid.
 
Click here to view how to quickly and economically fabricate a support table with individually replaceable 3/16" x 3" steel slats.