1、Designation: D6901 15Standard Specification forArtists Colored Pencils1This standard is issued under the fixed designation D6901; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses in
2、dicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification establishes requirements forcomposition, performance, and labeling of artists coloredpencils.1.2 This specification covers vehicles and addi
3、tives. Re-quirements are included for identification, lightfastness, andconsistency.1.3 Colored pencil specimens are exposed to both naturaldaylight through window glass and simulated window glass-filtered daylight radiation to determine the lightfastness ratingfor each pencil.1.4 The values stated
4、in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.2. Referenced Documents2.1 ASTM Standards:2D2244 Practice for Calculation of Color Tolerances andColor Differences from Instrumentally Measured ColorCoordinatesD4236 Practice for Labeling Art Mater
5、ials for ChronicHealth HazardsD4303 Test Methods for Lightfastness of Colorants Used inArtists MaterialsE284 Terminology of AppearanceG24 Practice for Conducting Exposures to Daylight FilteredThrough GlassG113 Terminology Relating to Natural and Artificial Weath-ering Tests of Nonmetallic MaterialsG
6、151 Practice for Exposing Nonmetallic Materials in Accel-erated Test Devices that Use Laboratory Light SourcesG155 Practice for Operating Xenon Arc Light Apparatus forExposure of Non-Metallic Materials3. Terminology3.1 DefinitionsRefer to Terminology E284 for appearanceterms used in this specificati
7、on and to Terminology G113 forterms relating to natural and artificial lightfastness tests.3.2 Definitions of Terms Specific to This Standard:3.2.1 bloom, na cloudy exudation on the surface ofcolored pencil due to wax migration.3.2.2 burnish, vto firmly rub the surface of the samplefollowing applica
8、tion of the colored pencil until the binderbreaks down and the color is forced into the texture of thesubstrate to improve coverage.3.2.3 colored pencil, na core of extenders, binders, pig-ments and additives, such as wax/oil and thickeners surroundedby a casing.3.2.4 color stick, na core of extende
9、rs, binders, pigmentsand additives, such as wax/oil and thickeners without a casingbut sometimes with a paper sleeve.3.2.5 substrate, nwhite, uncoated, neutral pH, bufferedpaper, or board, without optical brighteners, to which color isapplied.3.2.6 watercolor pencil, na colored pencil with a water-d
10、ispersible core.3.2.7 water-soluble color stick, na water-dispersible colorstick.4. Significance and Use4.1 This specification establishes quality requirements andprovides a basis for common understanding among producers,distributors, and users.4.2 It is not intended that all pencils meeting the req
11、uire-ments be identical nor of uniform excellence in all respects.Variations in manufacture, not covered by this specification,may cause some artists to prefer one brand over another, eitherof which may be acceptable under this specification.4.3 Variation in test results can result from differences
12、inpigment manufacture from time to time in a company, differentvarieties of a pigment from company to company, differentcombinations of pigments and other ingredients, specimenpreparation, different instruments and instrumental readings,variations in the surface of the specimen, and the conditions o
13、f1This specification is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.57 on Artist Paints and Related Materials.Current edition approved June 1, 2015. Published June 2015. Originallyapproved
14、in 2003. Last previous edition approved in 2006 as D6901 06 which waswithdrawn January 2015 and reinstated in June 2015. DOI: 10.1520/D6901-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards vo
15、lume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1exposure. Allowance for these variations is made by establish-ing lightfastness categories, each of whic
16、h covers a definedrange of color loss.4.4 Since a specific colored pencil may be unusually sensi-tive to some aspect of a particular method of acceleratedlightfastness testing and show a change in color that would notoccur in a normal home or gallery environment, two types ofexposure are required.4.
17、5 Some variation in test results is to be expected evenwhen the same type of exposure is repeated; therefore, aftertriplicate specimens are exposed in each type of exposure, anyoutlier is discarded and the mean of the specimens is calculatedfor each exposure type to determine the lightfastness categ
18、oryfor each. If the two types of exposures place colored pencil inthe same lightfastness category, it is the category for thatpencil. Instead of testing a third time if the two types ofexposures place the colored pencil in different lightfastnesscategories, producers may elect to use the poorer of t
19、he tworelevant lightfastness categories.4.6 Variations in specimen preparation and measurementmay result in as much as 4 units of CIE 1976 L*a*b*(CIELAB) color difference E*, calculated using the equationgiven in Practice D2244, between the measurements of a testspecimen before and after exposure; t
20、herefore, only colordifferences greater than 4 E* are considered color loss.5. Labeling Requirements5.1 Provide on the Pencil:5.1.1 Company or brand name.5.1.2 Company assigned identification number for thepencil, or company assigned color name for the pencil, or both;however, pigment names shall no
21、t be used as pencil namesunless the pencil contains only that pigment, or a variant of thatpigment, or that pigment and white; otherwise the word “Hue”must be added to the name.5.1.3 Country of origin.5.1.4 The Colour Index Names of the pigments used in thepencil if space permits.5.1.5 Lightfastness
22、Lightfastness Category indicated bythe symbols I, II, III, IV or V. Only colored pencils inLightfastness Categories I and II conform with this Specifica-tion.5.2 Provide in Literature Included in Packaging Containerand at Points of Purchase:5.2.1 Identification of the type of pencil: colored,waterco
23、lor, color stick, water-soluble color stick.5.2.2 Name and address of manufacturer, importer or sup-plier.5.2.3 The Colour Index name and Constitution Number ofevery pigment in each pencil.5.3 ToxicityAll products and labeling must conform to theFederal Hazardous Substances Act and to ASTM PracticeD
24、4236.5.4 Statement of ConformanceProvide Statement of Con-formance in literature and on packaging container if all pencilsin the container are Lightfastness I or II: “Conforms to ASTMSpecification D6901,” or “Conforms to ASTM D6901.” Thisstatement may be combined with other conformancestatements, su
25、ch as, “Conforms to the quality and healthrequirements of ASTM Specification D6901 and PracticeD4236.”6. Quality Assurance for Artists Colored Pencils6.1 Conditions Not Covered in This Specification that AffectColored Pencils:6.1.1 SubstrateThe effective pH of the paper used willaffect the long-term
26、 color appearance of the applied color.6.2 AdditivesThickeners, preservatives, surfactants, wax,oil, and humectants may be used to achieve consistency,prevent microbial deterioration, and control application results.6.3 Pencils shall be capable of being applied in a smooth,uniform coating of color w
27、ithout scratch marks.6.4 The colored lead shall not crumble or break excessivelywhen used with pressure sufficient to apply the color smoothly.7. Specimen Preparation and Exposure7.1 Materials:7.1.1 Colored Pencils, Watercolor Pencils, Color Sticks orWater-soluble Color SticksMaterials to be tested.
28、7.1.2 SubstrateWhite paper or board. To avoid substratediscoloration during the testing procedures, the substrate shallbe 100 % cotton, acid free, buffered, uncoated, and contain nooptical brighteners.7.2 Preparation of Test Specimens:7.2.1 Prepare ten specimens of each pencil or stick to betested.
29、Cut the paper substrate into a size that fits the holder tobe used for exposure. Draw a specimen square 28 by 28 mm(118 by 118 in.) in the center of each paper substrate. Leaveenough white substrate around each specimen so that thecolored portion will not be damaged by handling or instrumentmounting
30、 hardware. Using constant pressure, color each speci-men substrate evenly and firmly with the colored pencils,watercolor pencils, color sticks, or water-soluble color sticks.Repeat as necessary to completely cover the square drawn onthe substrate. In the case of a metallic color, finish with paralle
31、lstrokes in whichever direction results in an even metallicsheen. Burnish each sample to make coverage as complete anduniform as possible.NOTE 1It is difficult to achieve an even coating of the color withcomplete hiding of the substrate. If the substrate is not completelycovered, measurement will va
32、ry from spot to spot. If the coating hasvarying thicknesses, the specimen will fade unevenly. In these cases thecomplete surface of the substrate in the colored area may have to bemeasured to get a repeatable and reproducible measurement that repre-sents the average color of the specimen. If a 25 mm
33、 (1 in.) diameterinstrument measuring port is used, the whole colored surface of thespecimen is measured; if a smaller measuring port is used, additionalmeasurements of different portions of the colored surface of the specimenare necessary to accurately represent the color.7.3 Color Measurement Prio
34、r to Exposure:7.3.1 Prior to conducting the measurements described in7.3.2, gently wipe each specimen with cotton to remove anysurface bloom. Repeat this step immediately before specimenexposure.D6901 1527.3.2 The color difference among the ten replicate speci-mens and the uniformity of color on eac
35、h specimen shall be 4 and 8 to LightfastnessCategory II.9.4 For information and to establish nomenclature, thefollowing ratings are listed. Colored pencils with these ratingsdo not conform to this specification.D6901 1549.4.1 Lightfastness IIIAssign colored pencils that exhibita mean color change of
36、 E*ab8 and 16.0 to LightfastnessCategory III.9.4.2 Lightfastness IVAssign colored pencils that exhibita mean color change of E*ab16 and 24 to LightfastnessCategory IV.9.4.3 Lightfastness VAssign colored pencils that exhibit amean color change of E*ab24 or have lost all but a trace ofcolor to Lightfa
37、stness Category V.10. Report10.1 It is assumed that this report will be written after alightfastness test conforming to Specification D6901 has beencompleted on a group of colored pencils. The following appliesto reports for both methods:10.1.1 Name of company.10.1.2 ASTM test methods used.10.1.3 Co
38、lored pencil type.10.1.4 Colour Index Names and Constitution Numbers ofevery pigment in each pencil for all colored pencils tested.10.1.5 Date when exposure began.10.1.6 CIELAB values of L*, a*, and b* for test specimensprior to exposure.10.1.7 Date when test specimens were removed fromexposure, and
39、 total exposure time.10.1.8 CIELAB values of L*, a*, and b* for test specimensfollowing exposure. If it is not possible to measure specimensimmediately after removal from exposure, give the date whenmeasured.10.1.9 Lightfastness category for all test specimens asdetermined in Section 9.10.2 The foll
40、owing is specific information required for eachof the test methods:10.2.1 Test Method A:10.2.1.1 Total radiant exposure, in MJ/m2.10.2.2 Test Method B or Test Method C:10.2.2.1 Name and model of apparatus used.10.2.2.2 Exposure cycle used (100 % light or light/darkcycle).10.2.2.3 Irradiance level an
41、d tolerance limits in W/(m2nm)at 340 nm, at the machine control point.10.2.2.4 Radiant exposure at 340 nm, in kJ/(m2nm).10.2.2.5 Relative humidity, if measured.10.2.2.6 Uninsulated black panel temperature. If light anddark periods are employed, then uninsulated black paneltemperature must be listed
42、for each period.10.2.2.7 Chamber air temperature, if measured. If light anddark periods are employed, then the chamber air temperaturemust be listed for each period.10.2.2.8 Specimen repositioning schedule, if used.11. Keywords11.1 colored pencils; daylight through window glass; light-fastness; qual
43、ity requirements; test specimens; xenon arcexposuresAPPENDIX(Nonmandatory Information)X1. RATIONALEX1.1 This specification includes a method for placing col-ored pencils in general lightfastness categories that can becommunicated to artists on labels and literature. The testmethod must not only prov
44、ide accurate information to artists,but also ensure that different companies testing the sameformulation at different times and using different combinationsof the xenon arc machines (simulating daylight through win-dow glass) and window glass filtered natural daylightexposure, will place the pencil
45、in the same LightfastnessCategory. The following studies have been conducted to selectthe appropriate test conditions for colored pencils.X1.1.1 Round Robin 1Two specimens of fifteen coloredpencils were exposed in six types of accelerated exposure,three exposures under glass to natural summer daylig
46、ht, two ofthese in south Florida and one in Arizona; and three exposuresin different xenon arc machines filtered to simulate daylightthrough window-glass. Four papers used as substrates and a setof eight PPLF Reference Standards were included in theexposures. The Florida and Arizona exposures in Typ
47、e Acabinets were eliminated due to excess moisture and summerheat, respectively. Type A and Type B cabinets are described inPractice G24. Using the procedure given in Test MethodsD4303 80 % of the pencils were placed in the same lightfast-ness category no matter which combination of the remainingnat
48、ural and xenon arc exposures were selected; however, manyof the pencils fell in the poorer categories, which do notconform with the specification.X1.1.2 Round Robin 2Five colored pencils were selectedthat fell on the borderlines between Lightfastness Categories I,II, and III in Round Robin 1. Tripli
49、cates of each color and aPPLF Reference Standard 4 were exposed under glass tonatural daylight in three Type B cabinets in Florida. Two werewinter exposures and one a summer exposure. Triplicates ofthe same pencils were also exposed in five xenon arc machineswith window-glass filters. Two machines could monitor irra-diance at 340 nm. The ability to monitor irradiance at 340 nmwas established as significant, and moisture in the FloridaD6901 155boxes remained a concern. The largest variation in test resultswas due to incomplete hiding of the su
