Drawing board

Claim 1

A DRAWING BOARD COMPRISING A SUBSTANTIALLY RECTANGULAR FRAME OF TOP AND BOTTOM SOLID WOODEN ELONGATED BEAM-LIKE BLOCKS OF UNIFORM THICKNESS CONNECTED AT THE OPPOSITE ENDS BY END BLOCKS OF THE SAME THICKNESS AND LIMITED WIDTH TO FORM A CLOSED FRAME ENCLOSING AN INNER AREA SUBSTANTIALLY GREATER THAN THE AREA OF SAID BLOCKS, RIGID COVER SHEETS OF SIMILAR PLYWOOD OF AT LEAST 3 PLIES EXTENDING ACROSS THE OPPOSITE SURFACES OF SAID FRAME AND SECURELY AFFIXED THERETO ADJACENT THE EDGES THEREOF, SAID PLYWOOD COVER SHEETS BEING SUBSTANTIALLY COEXTENSIVE IN AREA WITH SAID FRAME AND THINNER THAN SAID FRAME AND BEING FINISHED SIMILARLY ON THE EXTERIOR SURFACES THEREOF, ADDITIONAL WOODEN BLOCKS OF EQUAL THICKNESS TO THOSE FORMING SAID FRAME AND EXTENDING TRANSVERSELY BETWEEN SAID TOP AND BOTTOM BLOCKS OF SAID FRAME AND FASTENED AT THEIR ENDS THERETO, SAID ADDITIONAL BLOCKS BEING WIDER THAN SAID END BLOCKS OF SAID FRAME AND SPACED FROM EACH OTHER LONGITUDINALLY OF SAID FRAME AND SUBSTANTIALLY EVENLY INWARD FROM THE OPPOSITE ENDS OF SAID FRAME TO BRACE SAID FRAME AND PROVIDE MEANS FOR THE ATTACHMENT OF SUPPORTING MEANS TO SAID BOARD, AND WOODEN SPACING MEANS OF EQUAL THICKNESS TO SAID FRAME POSITIONED WITHIN SAID FRAME BETWEEN SAID COVER SHEETS AND FIXED THERETO AT SPACED LOCATIONS OF RESTRICTED AREA GENERALLY THROUGHOUT THE FULL EXTENT OF AT LEAST THE CENTRAL PORTION OF SAID BOARD TO PREVENT MOVEMENT OF SAID COVER SHEETS TOWARD EACH OTHER AND PROVIDE A LIGHTWEIGHT DRAFTING BOARD WHICH IS SUBSTANTIALLY INSUSCEPTIBLE TO WARPING.