a standard tennis court 10 has playing surface 18 that is bordered by base lines 11 on two of the four sides . base lines 11 intersect at right angles with each of singles side lines 12 and doubles side lines 13 . service lines 14 are between lines 12 and are connected by center service line 15 that is a perpendicular bisector of each of lines 14 and extends under net 16 between each of service lines 14 . each of lines 11 , 12 , 13 , 14 , and 15 are boundary lines and are similarly treated . in one preferred embodiment , the court is treated as follows : to the outside of baselines 11 , apply the receiving composition approximately 6 inches outward from the line ( see fig1 enlargement , region b ), baseline 11 is 4 inches wide ( see fig1 enlargement , region a ), receiving composition is applied over baselines 11 ; and inside baseline 11 , apply the receiving composition approximately 4 inches inward ( see fig1 enlargement , region c ). fig1 is not drawn to scale . the above measurements describing application of the receiving composition are given by way of example . additionally , the application of the receiving composition may be to any desired distance in relation to the boundary lines . next to service lines 14 , apply the receiving composition approximately 6 inches outward from the line ( i . e . from the service line 14 in the direction of base line 11 ), service lines 14 are 2 inches wide , receiving composition is applied over service lines 14 ; and inside service lines 14 , receiving composition is applied approximately 4 inches inward . next to center service line 15 — apply the receiving composition on either side of the center line 15 approximately 4 inches and over center line 15 which is typically 2 inches wide . singles side lines 12 and doubles side lines 13 are each treated identically . apply the receiving composition approximately 6 inches outward from the lines 12 and 13 , lines 12 and 13 are 2 inches wide , receiving composition is applied over lines 12 and 13 ; and inside lines 12 and 13 , receiving composition is applied approximately 4 inches inward . the ball compression itself would be approximately 2 inches when striking the court and therefore the distances given for application of the receiving composition is contemplated as being acceptable to many tennis officials . these distances were contemplated based on the range of measurement currently utilized by the cyclops ® system . currently , the cyclops ® system measures 45 cm outside the line service line and 10 cm inside the service line . as seen in the expansion of fig1 , base line 11 has a width a . the invention encompasses treating the surface of court 10 with a receiving composition . each of lines 11 , 12 , 13 , 14 , and 15 are similarly treated ( although only one such expansion is shown in the figures ). a receiving composition 24 is applied a distance b outside said base line 11 , over said line 11 , and a distant c inside boundary line 11 . the total treated distance of a plus b plus c is distance d , which includes the width of the line 11 and the aforementioned applications of b and c . a conventional tennis ball 30 comprises visible seems and fibers . ball 30 is treated with striking composition 20 . felt ball fibers 25 have fiber dye 26 disposed thereon and further have dye on nodes 27 where fibers 25 typically intersect . ball 30 may have any part thereof containing striking composition 20 . preferably , a majority of the ball is coated with composition 20 . when ball 30 treated with striking composition contacts a surface treated with a receiving composition , a chemical reaction occurs due to the interaction of the chemical components in each of striking composition and receiving composition , creating a colored impression on the tennis court . fig2 - 5 demonstrate various impressions left when the present invention is used . as depicted in fig2 , impression 31 indicates the spot where ball 30 has contacted surface 18 that has been treated according to the present invention . fig2 depicts an impression 31 indicating ball 30 landed on the inside of the boundary line contacting both line 11 and surface 18 creating impression 31 . fig3 depicts impression 32 whereby ball 30 contacted surface 18 outside end line 11 . fig4 depicts impression 33 indicating ball 30 contacted end line 11 on end line 11 and impression 33 extended to the outer part portion of end line 11 . fig5 depicts impression 34 of ball 30 indicating ball 30 landed within the boundary of end line 11 . court surface 18 is typically painted with conventional tennis court paint and coatings as are commonly used and known in the art . tennis courts are typically marked with boundary lines 23 standard to the game of tennis . receiving composition 24 is subsequently disposed on and next to each of lines 11 , 12 , 13 , 14 , and 15 on surface 18 . referring to fig6 , surface 18 has been prepared with court paint 22 , line 23 , and receiving composition 24 . examples are given as demonstrative and are not intended to be limiting the scope of the invention . most of the examples used a combination of court coating and ball treatment . objectives were to obtain clear , colorless , non - glossy coatings over conventional tennis court surfaces , distinctive color changes upon impact from tennis balls on the special coating , fast removal of markings on the special coating , and no color change on the tennis balls ( or easily reversible color changes ). schenectady ® resin hrj 40234 ( si group , schenectady , n . y .) 8 ml was combined with schenectady ® 14894 microcapsules 32 ml , and a commercial acrylic latex , minwax ® 1265k 16 ml ( approximately 30 % solids by weight ). this material was brushed onto a dark green tennis court coating , world class athletics ® # tcp065 ( world class athletic surfaces , leland , miss .) on a hardboard , target tennis balls were hit to impact the target and markings were inspected and photographed . bluish - purplish marks were evident , with oval shapes , indicating that the single - paper system of carbonless carbon paper could provide a marking . however scuffs from tennis shoes also marked the coating the same color , indicating that these commercial materials would not be satisfactory for use as a ball impact marking system . we perceive that a stronger shell might be able to respond differently to ball impacts and shoe impacts and may be workable in a single coating system . an alkaline latex court coating was made with cornstarch , 5 gm stirred into water , 20 ml . this was added to sodium hydroxide , 2 gm , dissolved in water , 20 ml . the resultant mixture was added to minwax clear acrylic latex , 15 ml giving a smooth white mixture , easy to brush , but difficult to spray . tennis balls were treated with alum mordant and then were contacted with a solution of phenol red dye , 0 . 5 gm dissolved in denatured alcohol , 10 ml , plus ethoxyethane , 10 ml . the balls turned an orange color , and they were rinsed five times with denatured alcohol to remove superficial dye . tennis ball impacts of these balls on a target with the c - 2 coating gave discernible , but not distinct marks . a court coating was made 0 . 5 grams of crystal violet lactone dye dispersed in kwal ® ( kwal paint , denver , colo .) brand of satin acrylic latex , 15 ml . a tennis ball was treated with a solution of salicylic acid , 32 grams in denatured alcohol , 400 ml ( overnight contact , water rinse , dried ). the ball was pressed onto the ccp - 6 coating and rotated a quarter turn . it made no mark on the coating . a drop of this salicylic acid solution on the coating caused color change to blue , but it was difficult to discern the color difference between the blue and the green background . a court coating was made with schenectady 14508 developer , 996 ml , exsilon ® 9 acidic clay pigment ( engelhard corporation , iselin , n . j .) 80 gm , dispersed in 25 ml of water , mixed with minwax ® acrylic latex ( minwax company , upper saddle river , n . j .) 12 ml . this off - white coating was applied over tcp065 dark green . tennis balls were treated with alum mordant ( 15 grams / gallon of water , heat at 150 ° f . for 1 hour , cool , rinse with water , dry ) and they were then dyed with a solution of crystal violet lactone ( cvl ), 5 grams in toluene , 100 ml and ethylene glycol methyl ether , 10 ml . solution contact was about 15 seconds , followed by baking at 150 ° f . the tennis balls had very little color change . where contacted with a drop of salicylic acid solution , the color changed to blue , and microscopic examination showed that the dye was absorbed by the wool fibers of the tennis ball . the tennis balls with the crystal violet dye were hit at the target with the coating of example 4 , and showed readily discernible marks on the coating ( good ) and on the tennis balls ( undesired , but reversible by exposure to vapors of ammonium hydroxide ). a tan coating was prepared for better discrimination of color change using schenectady microcapsule dispersion # 18894 , 64 ml , added to kwal ® brand of satin latex , color # 8264d , 12 ml . tennis balls were prepared using 32 grams of salicylic acid dissolved in 400 ml of denatured alcohol ( overnight contact , water rinse , dried ). ball impacts on this coating gave chalky markings on the target with little color change from the dye . schenectady ® 4508 developer , 96 ml , was added to minwax clear acrylic latex , 12 ml , and was applied as a relatively clear , colorless coating over dark green world class athletics tcp065 on a panel . ball treatment was with cvl dye as noted above . ball impacts gave dark bluish coloration on both the coating and on the balls . ball drops from 6 - foot height did not give a mark . dark marks on the ball could be removed by exposure to vapors of ammonium hydroxide . schenectady ® 4508 developer , 96 ml , was added to minwax ® clear acrylic latex , 12 ml and was applied over dark green tcp065 panel . b - 14 ball treatment was made with 5 grams of malachite green lactone dye dissolved in 100 ml of toluene . this solution was sprayed onto a rotating ball held with spiders on a slowly rotating lathe . spraying was accomplished with an airbrush about 4 inches away from the ball and air pressure about 35 psi . the ball was dried at room temperature and then baked 1 hour at 150 ° f . a drop of salicylic acid on the ball gave indication of good dye absorption into the felt fibers . ball hits on white striping paint were distinct , those on the dark green court were not distinct , and there was little impact marking on the balls . balls with b - 2 treatment were very distinct on white striping paint and fairly distinct on the dark green . schenectady ® dry resin # hrj2053 , 20 grams , was added to gemini 160 sanding sealer ( a nitrocellulose - based lacquer ), 50 ml , diluted with methyl ethyl ketone , 10 ml and diethylhexylphthalate plasticizer 1 ml . this coating had little color or cloudiness and less gloss than ccp - 7 . impact of balls with b - 2 treatment gave good color change on this coating . salicylic acid , 10 grams , diethylhexylphthalate plasticizer , 1 ml , and schenectady ® solid phenolic resin # 2053 , 1 gm , were added to 50 ml of denatured alcohol . this gave a hard , non - glossy coating with slightly milky appearance and sparkles from crystals on the surface . balls b - 2t were made by pre - dyeing tennis ball felt with a solution of crystal violet lactone ( cvl ), 2 grams , in toluene , 100 ml . the felt had been pre - treated with an alum mordant solution , 15 grams in 1 gallon of water , 1 hour at 150 ° f ., rinsed with water and dried . tennis balls were then made from this felt by wilson sporting goods , inc . following their normal fabrication process . balls b - 18 were made with a spray of dye solution made from noveon specialty yellow # 37 ( noveon inc ., cleveland , ohio ), 2 grams , toluene , 100 ml and propylene carbonate , 2 ml . after spraying , the balls were placed in a ball tube for 1 hour , then they were washed with water to remove the propylene carbonate and they were dried . impacts with both ball treatments gave distinctive markings on white striping , and the yellow markings were better on green than the blue markings . the b - 18 balls did not have any color change from impact with the ccp - 54 coating . oxalic acid , 10 gm , mantrose - haeuser refined , decolorized shellac # r - 49 ( mantrose - haeuser company , westport , conn . ), 1 gm , denatured alcohol , 50 ml . this coating had no gloss , no color , and better initial appearance than above examples . sprayed onto panel for testing using airbrush . treatment on ball was noveon specialty orange # 14 , 2 grams , xylene , 98 ml , propylene carbonate , sprayed , placed in ball can for 1 hour , washed with water , dried . fair color distinction with impact of balls with the b - 24 orange and the b - 2 blue dyes . colors faded significantly over 24 - hour period . oxalic acid , 10 gm , polyvinylpyrollidone k - 30 , 1 gm , water , 50 ml gave non - glossy , colorless coating , slow dry . b - 28 ball treatment used noveon magenta # 16 dye , 2 gm , xylene , 100 ml , propylene carbonate 2 ml , sprayed onto tennis ball , held in ball can 1 hour , then washed with water and dried . system gave good color distinction when swatch of b - 28 magenta was pressed and turned against the coating , fair color with b - 18 yellow and b - 24 orange dye treatments . the above examples all used solvent dyes . because wool fibers are proteinaceous , they are often dyed commercially with acidic dyes . the following examples use acidified solvents that dye the felt of a tennis ball with the converted color . this provides a means of quickly confirming that a good dye penetration has been accomplished . the dyed felts are then converted back to their intended color by using ammonia vapor or other neutralizing chemicals . alkaline chemical added to acrylic court coating , e . g . sodium silicate , sodium tetraborate , either while wet or impregnated after dry , with a phenolphthalein - type color change going from neutral to alkaline . because ball marks needed to be removed frequently and quickly ( about 90 seconds are available during court direction changes after sets 1 , 3 , 5 . . . ) examples of color removal systems are shown . treatment with alkali is one means of converting the dye back to its original colorless chemistry , but residual , nonvolatile alkali neutralizes the acidity of the ccp coating and makes it inactive in the case of a second hit by the ball in the area that has been treated . most of the leuco dyes are soluble in aromatic solvents and other solvents having a relatively low hildebrand solubility parameter . dissolution of the dye and wiping to remove it is a means of decolorizing the ball mark , if the solvent does not also dissolve and remove the acid in the special coating . ammonium bicarbonate , 10 grams dissolved in 50 ml water + 50 ml methanol was sprayed onto ball impact marks and was dried with a heat gun without wiping . yellow and orange marks disappeared quickly , but blue and magenta colors did not go colorless . salicylic acid 10 grams dissolved in denatured alcohol , 50 ml with schenectady ® phenolic resin 2053 1 gm and diethylhexyl phthalate 1 ml was sprayed onto ball impact marks . the marks immediately became more intense by virtue of the additional acidity and dissolution of the dye . the marks were blotted with a soft cloth or paper towel to remove the dissolved dye . the residual coating remained active for marking subsequent ball hits . a commercial solution of xylene , methanol , acetone and heptane was sprayed onto ball impact marks and it was promptly blotted with a paper towel , removing the marks , but leaving the surface de - activated for subsequent ball hits . glacial acetic acid was sprayed onto a ball mark and was blotted dry . within 20 seconds , the color of the mark disappeared . the preferred remover / activator is formula r - 19 , a solution of salicylic acid , 10 grams and pvp k - 30 1 gram , in methanol 30 ml and toluene 30 ml with 1 ml of lactic acid . these test were repeated to confirm surface activity after the removing steps . while the invention has been described in its preferred form or embodiment with some degree of particularity , it is understood that this description has been given only by way of example and that numerous changes in the details of construction , fabrication , and use , including the combination and arrangement of parts , may be made without departing from the spirit and scope of the invention .
the present invention is an article and process for determining the site of impact of a movable object on a treated surface , where a tennis ball is treated with a striking composition , and a boundary line region is treated with a receiving composition such that when the striking composition and the receiving composition are in physical contact , a colorimetric indicator is left on the receiving composition to indicate the point of contact .