the present invention is a vacuum table especially useful in holding a workpiece to a surface for engraving or other purposes . referring to the figures , the table 50 is made up of a vacuum plate 10 , a replaceable mat 52 on which work items may be held , and a vacuum assembly 54 . referring to fig1 , and 11 , the vacuum plate 10 forms a base for the table 50 . the mat 52 has been omitted from fig1 for simplicity , as this mat is identical to those appearing in fig1 and 7 . in a preferred embodiment , the plate 10 is made from aluminum . the plate 10 is preferably rectangular and defines a groove 56 ( fig2 - 3 ) about its perimeter . an aperture 14 ( fig4 ), ultimately used to pull air to the vacuum pump , is defined by the plate 10 . a pair of graduate rules 16 preferably bound the plate 10 at its uppermost and leftmost sides permit measurement of a workpiece on the table . a gasket 18 mounts within the perimetric groove 56 of the vacuum plate 10 . the gasket 18 may be secured with adhesive on its underside to the vacuum plate 10 . protruding slightly above the level of the plate , the gasket 18 may later be compressed to form an air tight seal with the mat . the protrusion of the gasket 18 above the plate will preferably be 0 . 020 inch . referring to fig1 , and 7 , the plate 10 may include a plurality of holes 58 along its edges for mating with the guide pins on the workholding vise assemblies of engraving machines having such workholders . portions of the vacuum assembly 54 , described in detail below , may attach to the bottom surface of these plates 10 . alternatively , referring to fig3 and 11 , the plate 10 may be completely planar for mounting on the t - slot tables of engraving machines having these alternative workholders . the vacuum assembly 54 must attach to the end of such plates 10 , with the appropriate airflow passages contained within the plates 10 , as is also explained in detail below . a replaceable mat 52 is mounted on the vacuum plate 10 , engaging the gasket 18 . an airtight seal is formed by the gasket 18 when vacuum is applied to the system . the mat 52 forms the work surface to which a work piece w is ultimately held by the vacuum forces . the mat 52 has two layers , a base sheet 40 and a rubber sheet 50 , preferably adhered to one another by an adhesive layer 60 . the base sheet 40 is preferably formed of polyvinyl chloride ( pvc ) plastic . the base sheet 40 defines an upper surface 42 to which the rubber sheet 50 is affixed , and a lower surface which engages the gasket 18 . a plurality of perforations 46 are defined by the base sheet 40 . each perforation is preferably one quarter of an inch in diameter , although other sizes may be used . the perforations 46 are arranged in an orderly fashion , each preferably separated by a distance of one half inch . each perforation passes completely through the base sheet 40 , from the upper surface 42 through the lower surface . a network of channels 48 interconnect each perforation . the channels 48 are defined only on the lower surface , and do not pass completely through the base sheet 40 . the resilient upper sheet 50 is affixed , with adhesive , to the upper surface of the base sheet 40 . resilient sheet 50 is preferably made from rubber . a plurality of pin holes 52 , preferably 0 . 004 inch in diameter , are aligned with and centrally disposed above each perforation of the base sheet 40 . when a vacuum is applied under the base sheet 40 , portions of the rubber sheet 50 are pulled into the perforations 46 , resulting in a plurality of suction - cup like indentations 54 of the rubber sheet 50 . it is these suction - cup like indentations 54 which ultimately engage and hold a workpiece in place on the vacuum table , as best seen in fig5 . the vacuum assembly 54 preferably is one of the three embodiments described below . the first vacuum assembly 54 , for a workholding vise assembly , is illustrated in fig1 , 4 , and 6 . the aperture 14 , passing completely through plate 10 , connects to hose 28 , preferably by pipe - tapping aperture 14 . hose 28 includes a slide valve regulator 24 , which is preferably configured as a tube encircling the hose 28 . the slide valve regulator 24 reciprocates between a closed position wherein it covers an aperture 25 in hose 28 , and an open position wherein it exposes the aperture 25 . when the aperture 25 is covered , all air flow into hose 28 must be from aperture 14 , maximizing suction at plate 10 , whereas opening aperture 25 allows air to enter hose 28 through aperture 25 , reducing suction at plate 10 . hose 28 connects at its opposite end to a pressure gauge 22 , air filter 60 , and finally to vacuum pump 62 . the vacuum pump 62 supplies vacuum pressure to the system , which can be measured by the pressure gauge 22 . the second embodiment of the vacuum apparatus 54 , for use with t - slot workholders , is illustrated in fig3 , 6 , and 11 . the aperture 14 passes only partially through plate 10 , and connects with pipe - tapped air passage 64 . the pipe - tapped air passage 64 connects to hose 28 . hose 28 includes a slide valve regulator 24 , reciprocating between a closed position wherein it covers an aperture 25 in hose 28 , and an open position wherein it exposes the aperture 25 . when the aperture 25 is covered , all air flow into hose 28 must be from aperture 14 , maximizing suction at plate 10 , whereas opening aperture 25 allows air to enter hose 28 through aperture 25 , reducing suction at plate 10 . hose 28 connects at its opposite end to a pressure gauge 22 , air filter 60 , and finally to vacuum pump 62 . the vacuum pump 62 supplies vacuum pressure to the system , which can be measured by the pressure gauge 22 . the third embodiment of the vacuum apparatus 54 includes a manifold block 20 mounted under the vacuum plate 10 . the manifold block 20 includes a vacuum gauge 22 for measuring the amount of vacuum pressure being applied by the system and a slide valve regulator 24 which are in fluid communication via conduits and hoses with the vacuum plate 10 and the vacuum pump . the manifold is connected at one end via a conduit 26 to the aperture 14 in the vacuum plate 10 and at another end via hoses 28 to the vacuum pump ( not shown ). the slide valve regulator 24 works to control the vacuum applied to the vacuum plate 10 . the slide valve selects between closing the system ( creating a vacuum ) and opening the system ( releasing the vacuum ). to close the system , the slide valve covers an opening 25 in the manifold block 20 forcing air to be evacuated from the vacuum plate 10 . in contrast , the opening 25 is exposed , causing the pump to pull from the path of least resistance , which leads to the open atmosphere , and the vacuum within the table is broken . in operation , a workpiece is place on the rubber sheet 50 of the mat , which is in place over the vacuum plate 10 . the vacuum pump is started , pulling air from the system . if the slide valve is open as seen in fig4 air is pulled from the atmosphere , and no vacuum is created within the table . once the slide valve is closed , as seen in fig3 the pump pulls air from within the table . ultimately , the internal vacuum pulls on the rubber sheet 50 through the perforations 46 in the base sheet 40 of the mat . the rubber sheet 50 is pulled partially into each perforation . the pulling of the rubber sheet 50 creates a small space between the rubber sheet 50 and the workpiece . the space also creates a vacuum which holds the workpiece in place , much like a suction - cup . the pin holes 52 in the rubber sheet 50 correspond to the center of each suction - cup like indentation thus formed . the work piece actually seals the cups allowing air to be drawn downward into the system , creating a plurality of miniature vacuum chambers . because the pin holes 52 are relatively tiny , the rubber sheet 50 is still pulled into the perforation of the base sheet 40 , but an additional amount of air is evacuated from the cavity formed between the rubber and the workpiece causing the workpiece to be held firmly in place until the system is opened via the slide valve . because the mat is replaceable and constructed of relatively inexpensive materials , it may be discarded if it becomes damaged . only the mat need be replaced , not the entire vacuum table . this design also obviates the need to send the table out for repairs in the event the surface becomes marred . a simple replacement of the mat readies the system for extended use . although the mat and vacuum table may be made in many different shapes and sizes , the preferred form is a rectangular table having a mat of any of the following dimensions : 3 . 5 by 9 inches , 8 . 25 by 12 . 25 inches , and 19 . 75 by 25 . 25 inches . the vacuum table is especially well suited for holding items for engraving applications , but may be used for other purposes . it is to be understood that the present invention is not limited to the sole embodiments described above , but encompasses any and all embodiments within the scope of the following claims .