in this example , a coating composition is prepared for use in manufacturing the sensitized record sheet of this invention . the active components are 3 , 5 - di - tert - butylsalicyclic acid , zinc oxide and ammonium hydroxide . as a first step , the active materials , that is , the salicylic acid derivative , the zinc compound and the ammonium hydroxide , are combined . the composition is then completed by adding whatever fillers , inactive pigments , and binders are required or desired . about 10 parts of salicylic acid derivative -- in this example , 3 , 5 - di - t - butylsalicylic acid -- and about 30 parts of zinc compound -- in this example zinc oxide -- are dispersed together in about 210 parts of water . a few parts of a dispersing agent can be used , if desired . about 16 parts of aqueous ammonium hydroxide solution ( 28 - 30 weight percent nh 3 ) is added to the combination with agitation . for best results , the system is permitted to stand for about 16 hours . about 70 parts of that dispersion is added to about 210 parts of 35 percent inactive kaolin clay in water and thoroughly mixed . to that mixture is added 100 parts of 10 percent , aqueous , cooked starch binder and 12 parts of 50 percent , aqueous , styrene - butadiene latex binder . the clay , the starch , and the latex are inactive materials and do not serve functional purposes insofar as the record sheet sensitivity is concerned . the clay is used as a filler material and the starch and latex are binder materials . the amount of any of those components is not critical and can be varied to a large extent . the filler materials are used as a matter of coating convenience and an improved and operable sheet is made if those materials are omitted altogether . in the first step , after addition of the ammonium hydroxide , the ph of the dispersion is above 8 . 0 . after the inactive clay and all of the other , additional , materials are combined , the ph is about 9 . 6 . for testing purposes , the formulation is coated onto sheets to achieve a dry coating weight of about 7 . 5 grams per square meter . when a sheet is made with only binders and active material and without inactive clay and other inactive filler pigments , the coating weight is only about 2 . 3 grams per square meter . here will be described a capsule - coated transfer sheet for use in testing the receiving sheets prepared in examples which follow . the capsules contain a liquid solution of chromogenic material and are prepared as follows : an aqueous emulsion having oil droplets of 2 to 3 microns diameter is prepared by mixing the following materials at 55 degrees centigrade . ( all water used herein is deionized water .) with continual stirring and maintenance of the temperature at 55 ° c ., the ph of the stirred emulsion is adjusted to 6 . 5 , and the emulsion is treated with 133 grams of 10 percent aqueous gum arabic solution and then diluted with 700 grams of water . the stirred mixture is then treated with 12 grams of 5 percent aqueous poly ( methylvinylether - co - maleic anhydride ) solution , added dropwise . about 15 milliliters of 14 percent acetic acid are added to adjust the ph to about 4 . 5 . with continued stirring , the mixture is cooled to about 15 ° c ., treated with 10 milliliters of 25 percent aqueous glutaraldehyde and allowed to stir at room temperature for about 48 hours . an aqueous slurry of the capsules is made up having the following composition : ______________________________________ parts ( wet ) ( dry ) ______________________________________capsules 485 100arrowroot starch granules 24 24cooked cornstarch 50 10water 41 -- ______________________________________ paper sheets are coated with the above slurry with a no . 15 mayer rod to give a dried coating weight of about 4 . 5 grams per square meter . for this example 1 ( a ) transfer sheet , the capsule contents include a solution mixture of substantially water insoluble liquids dissolving a mixture of four chromogenic materials . the liquids are about 60 percent of ethyl diphenyl methane , 30 percent of a saturated hydrocarbon oil with a distillation range of about 190 °- 250 ° c ., and 10 percent of heptyl undecyl phthalate . the chromogenic materials are dissolved in the liquid in total amount of about 3 . 3 percent of the liquid . the chromogenic materials are about 1 . 70 percent of crystal violet lactone , 0 . 50 percent of benzoyl leuco methylene blue , 0 . 55 percent of 2 &# 39 ;- anilino - 6 &# 39 ;- diethylamino - 3 &# 39 ;- methyl fluoran , and 0 . 55 percent of 3 , 3 - bis ( 1 - ethyl - 2 - methylindol - 3 - yl ) phthalide . the dried capsule coating is made to be about 3 . 0 - 3 . 7 grams per square meter . the formulations of the following examples are tested against the transfer sheets of example 1 ( a ). a capsule coated sheet surface is placed against a receiving sheet surface from the examples and the capsule coated sheet is struck in an image pattern using an electric typewriter . the capsules are ruptured and a colored image is formed where the released chromogenic materials contact the receiving sheet coating . the resulting pattern images are tested for print intensity by use of a reflectance spectrophotometer ( opacimeter ). typewriter intensity indexes are reported here for the receiving sheets described in examples 1 - 6 . a typewriter intensity index ( ti ) of 100 indicates no detectable print and the lower numbers indicate more intense prints , showing greater contrast with the background . generally , a typewriter intensity index of less than 60 , for a black print , indicates a print which is sufficiently intense to be esthetically pleasing and readily read by the human eye . initial typewriter intensity is designated as ( iti ). the typewriter intensity of a mark after aging 24 hours is designated as ( ati ). a mark exposed for 24 hours to ultraviolet radiation is designated as ( uvti ). a mark made using a receiving sheet which has been exposed for 24 hours to ultraviolet light before marking is designated as ( uv sheet ). to commence the comparisons , the sheets of example 1 , which is the preferred sheet of this invention , exhibited the following values : the same formulation is made in this example as was described in example 1 with the exception that the salicylic acid derivative is 3 , 5 - di - iso - propylsalicylic acid . the ph of the final composition is 8 . 9 . when no salicylic acid derivative is used the ph of the final composition is 10 . 1 ; and when unsubstituted salicylic acid is used the ph is 7 . 1 ( designated as example 2 ( a )). ______________________________________example iti ati uvti uv sheet______________________________________1 56 56 78 622 63 57 76 84 2 ( a ) 85 83 92 90______________________________________ the use of 3 - tert - butyl - 5 - methyl salicylic acid provides results comparable to those of 2 . increasing the ph when using unsubstituted salicylic acid does not appreciably alter the results of 2 ( a ). the same formulation is made in this example as was described in example 1 with the exception that sodium hydroxide is substituted for the ammonium hydroxide . the ph of the final coating composition is adjusted to be about 9 . 8 . ______________________________________example iti ati uvti uv sheet______________________________________1 56 56 78 623 79 68 89 88______________________________________ sodium hydroxide is an unacceptable ph adjusting material . similar results are obtained from potassium hydroxide . it is believed that ammonium hydroxide is especially suited for the coating system of this example because it is volatile and it is removed when the coating is dried . the same formulation is made in this example as was described in example 1 with the exception that , for purposes of the test , twice the amount of zinc oxide was used ( 60 parts of this example ) and a varying amount of ammonium hydroxide was used . the varying amounts of ammonium hydroxide and the coating system ph , are designated as follows , along with the test results . ______________________________________example parts nh . sub . 4 oh ph iti ati uvti uv sheet______________________________________1 16 9 . 6 56 56 78 624 ( a ) 0 7 . 2 83 78 90 854 ( b ) 4 8 . 2 71 64 84 714 ( c ) 8 8 . 7 56 56 77 624 ( d ) 12 9 . 3 60 58 82 664 ( e ) 16 9 . 6 59 58 79 624 ( f ) 20 9 . 8 59 59 82 64______________________________________ note that examples 4 ( c ), 4 ( d ) and 4 ( e ) yield very good results and that examples 4 ( b ) and 4 ( f ) yield results which are acceptable . the same formulation is made in this example as was described in example 1 with the exception that , for purposes of the test , a varying amount of 3 , 5 - di - tert - butylsalicylic acid is used . the varying amounts of salicylic acid derivative , and the resulting coating system ph , are designated as follows : ______________________________________ex - parts salicylic acid uvample derivative ph iti ati uvti sheet______________________________________1 10 9 . 6 56 56 78 625 ( a ) 0 10 . 1 89 88 93 905 ( b ) 4 9 . 7 73 70 88 835 ( c ) 10 9 . 6 59 58 79 625 ( d ) 16 9 . 3 55 56 74 615 ( e ) 22 8 . 8 55 56 73 59______________________________________ the same formulation is made in this example as was described in example 1 with the exception that , for purposes of the test , a varying amount of zinc oxide is used . the ph for the resulting coating system is constant within a narrow range of about 9 . 4 to 9 . 6 . the varying amounts of zinc oxide , and the resulting weight ratio of zinc compound to salicylic acid derivative are designated as follows : ______________________________________ ratio of zinc compound toex - parts zinc salicylic acid uvample compound derivative iti ati uvti sheet______________________________________1 30 3 56 56 78 626 ( a ) 0 -- 72 72 91 916 ( b ) 10 1 60 61 83 666 ( c ) 20 2 60 59 82 686 ( d ) example 1 , repeated 56 56 78 626 ( e ) 40 4 59 58 80 626 ( f ) 50 5 58 59 -- -- 6 ( g ) 60 6 59 58 79 62______________________________________ in the test of this example , a capsule transfer sheet is used which has capsules in an amount , and of a size , similar to those of example 1 ( a ), above . the substantially water insoluble liquid is a 2 - to - 1 solution mixture of 2 , 2 , 4 - trimethyl - 1 , 3 - pentanediol diisobutyrate and the hydrocarbon oil of example 1 ( a ). the same formulation is made in this example as was described in example 1 with the exception that , for purposes of the test , different zinc compounds are used . ______________________________________ex . zinc compound iti ati uvti uv sheet______________________________________1 zinc oxide 57 54 64 567 ( a ) zinc phenol sulfonate 66 59 71 697 ( b ) zinc carbonate 60 55 67 567 ( c ) zinc phosphate 76 66 77 79______________________________________ while the different zinc compounds do not yield test results as good as the preferred zinc oxide , they are acceptable . combinations of the zinc compounds can be used . materials with cations other than zinc are not found to be acceptable for use in this invention . as an additional matter of comparison , the zinc phenol sulfonate tested against the sheet of example 1 ( a ) yielded the following test results : iti - 58 ; ati - 58 ; uvti - 83 ; and uv sheet - 70 . in this example , test receiving sheets are prepared using a specially - prepared salicylic acid / formaldehyde polymer in the place of the salicylic acid derivative of example 1 . the polymer is prepared by reacting 138 parts of salicylic acid and 325 parts of formalin in 250 parts of 12 n sulfuric acid at 95 ° to 97 ° c for 1 hour . twenty parts of the resulting polymer are combined with 300 parts of ethanol and 100 parts of one of three , below - identified metallic compounds . this formulation is applied to sheets to yield coatings of about 5 - 6 grams per square meter . the above receiving sheet coatings are tested against the transfer sheet of example 1 ( a ) and the results are compared with the test results of the receiving sheet of example 1 , herein . the sheets of this example 8 contain more than seven times as much salicylic acid polymer as there is salicylic acid derivative in the sheets of example 1 . moreover , the sheets of example 8 contain more than ten times as much metallic compound . the different receiving sheets , identified by metallic compound , are set out below . the typewriter intensity indexes are provided for several time periods to show the speed of print development . ______________________________________ex . metallic compound iti 20 minutes 16 hours ati______________________________________1 zinc oxide 56 -- -- 568 ( a ) zinc oxide 84 79 78 768 ( b ) calcium carbonate 88 81 78 768 ( c ) zinc carbonate 84 80 76 74______________________________________ the receiving sheet formulations can be applied by several methods , as previously disclosed . in this example , several methods of such application are discussed . the receiving sheet of this invention can be made by adding components of the formulation of example 1 at selected positions on a paper making machine . for instance , the zinc compound can be added at the head box and the salicylic acid derivative can be added at a size press on the machine . an appropriate head box formulation is : ______________________________________ parts______________________________________hardwood kraft pulp 125softwood kraft pulp 125alum 1 . 25modified starch ( cationic ) 1 . 75water soluble rosin 1 . 00calcium carbonate 16 . 7 - 20 . 9zinc oxide 4 . 2 - 8 . 4acrylamide retention aid 0 . 1 - 0 . 2______________________________________ water is added to the pulp with agitation to a consistency of 3 . 0 - 3 . 3 ( percent over - dry fiber in water ) and this suspension is refined to a freeness of 340 ± 20 milliliters ). then the alum , rosin and fillers are added , and the ph is adjusted with ammonium hydroxide . starch and retention aid are finally added . ______________________________________starch gum 4 parts3 , 5 - di - tert - butyl salicylic acid 2 . 5 - 5 . 0ammonium hydroxide ( 28 %) 1 - 2water 90______________________________________ sheets made using the above head box formulation and coated at the size press yield test results comparable to the sheets of example 1 . analysis of the coating , as applied above , shows that the salicylic acid derivative is present at 0 . 2 to 0 . 4 grams per square meter and that zinc oxide is present at 1 . 0 to 1 . 8 grams per square meter . alternatively , the entire receiving sheet formulation can be built into the web at the head box or can be added to the web at a size press . for either alternative , care must be exercised to assure that the ratio of salicylic acid derivative to zinc compound is within the previously described ranges . an increased amount of active materials is required in the head box application to make up for loss of materials through the web , during web formation . the size press formulation may require an additional amount of adhesive binder . as another alternative , the coating formulation of example 1 can be applied onto a moving paper machine web from a curtain coating apparatus . in such an operation , the formulation is substantially as previously disclosed with the exception that additional water may be used for better control of the coating weight .