ASTM D6487-99e1
(Practice)Standard Practice for Preparing Prints of Paste Printing Inks With an Offset Color Proofing Press
Standard Practice for Preparing Prints of Paste Printing Inks With an Offset Color Proofing Press
SCOPE
1.1 This practice covers the procedure for preparing laboratory prints of paste inks utilizing an offset color Proofing Press. The initial method was developed by the National Printing Ink Research Institute.
1.2 This practice is applicable to the preparation of single-color solid-area prints by the dry offset process on a flat substrate such as paper or metal. It can readily be adapted to print by direct letterpress.
1.3 This practice is applicable primarily to lithographic and letterpress inks that dry by oxidation or penetration. With the addition of appropriate drying or curing equipment, it is also applicable to other systems such as heat-set or energy-curable.
1.4 The instructions in this practice are intended to minimize the within-print and among-operator variability inherent in hand operations.
1.5 This practice does not measure the actual film thickness on the print, but evaluates film thickness equivalence by visual or instrumental comparisons of optical density.
1.6 Values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the users of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific precautions are given in Section 7.
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Standards Content (Sample)
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e1
Designation: D 6487 – 99
Standard Practice for
Preparing Prints of Paste Printing Inks With the Little Joe
Offset Color Proofing Press
This standard is issued under the fixed designation D 6487; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
e NOTE—First millilitre value in 8.4 corrected editorially to 0.6 mL in April 2000.
1. Scope 2.2 ANSI Standards :
PH 2.17 Geometric Conditions for Reflection Density
1.1 This practice covers the procedure for preparing labo-
PH 2.18 Spectral Conditions for the Measurement of Opti-
ratory prints of paste inks utilizing the Little Joe Offset Color
cal Density
Proofing Press. The initial method was developed by the
PH 2.30 Viewing Conditions for Graphic Arts and
National Printing Ink Research Institute .
Photography—Color Prints, Transparencies and Photome-
1.2 This practice is applicable to the preparation of single-
chanical Reproductions
color solid-area prints by the dry offset process on a flat
CGATS.4 Graphic Technology–Graphic Arts Reflection
substrate such as paper or metal. It can readily be adapted to
Densitometry Measurements—Terms, Equations, Image
print by direct letterpress.
Elements and Procedures
1.3 This practice is applicable primarily to lithographic and
CGATS.5 Graphic Technology–Spectral Measurements and
letterpress inks that dry by oxidation or penetration. With the
Colormetric Computation for Graphics Arts Images
addition of appropriate drying or curing equipment, it is also
applicable to other systems such as heat-set or energy-curable.
3. Summary of Practice
1.4 The instructions in this practice are intended to mini-
3.1 The equipment is set up as described in Annex A1. In
mize the within-print and among-operator variability inherent
order to make a print, the test ink is metered onto a brayer,
in hand operations.
rolled out evenly on the distribution plate according to a
1.5 This practice does not measure the actual film thickness
specified pattern, and then transferred to the printing plate. The
on the print, but evaluates film thickness equivalence by visual
appropriate stock is clipped onto the impression plate, and the
or instrumental comparisons of optical density.
blanket cylinder is rolled over the inked plate six times
1.6 Values stated in SI units are to be regarded as the
followed by once over the stock.
standard. The values given in parentheses are for information
3.2 After the print is set, it is checked against the target
only.
optical density instrumentally or by visual comparison with a
1.7 This standard does not purport to address all of the
standard print. Subsequent prints are made until the target
safety concerns, if any, associated with its use. It is the
optical density has been achieved.
responsibility of the users of this standard to establish appro-
priate safety and health practices and determine the applica-
4. Significance and Use
bility of regulatory limitations prior to use. Specific precau-
4.1 Laboratory proofing of ink is necessary to establish a
tions are given in Section 7.
reproducible prediction of print appearance and performance
2. Referenced Documents properties, most of which are highly sensitive to ink film
thickness. The apparatus described in this practice has found
2.1 ASTM Standards:
wide use for routine control proofing because it provides an
D 6073 Test Method for Relative Setting of Headset Inks by
3 economical method for producing reasonably large prints at
the Sinvatrol Drier
film thicknesses comparable to those obtained on production
presses.
4.2 This practice does not duplicate the dynamics of a high
speed press, nevertheless, it is useful for quality control and for
These test methods are under the jurisdiction of ASTM Committee D-1 on Paint
and Related Coatings and Materials and is the direct responsibility of Subcommittee
specification acceptance between the producer and the user.
D01.56 on Printing Inks.
Current edition approved Dec. 10, 1999. Published February 2000.
“The NPIRI Standard Procedure for Preparing Little Joe Prints”, American Ink
Maker, March 1994, pp. 42-50. 4 th nd
Available from American National Standards Institute, 13 Floor, 11 W. 42
Annual Book of ASTM Standards, Vol 06.02.
Street, New York, NY 10036 or Committee on Graphic Arts Technical Standards,
1899 Preston White Drive, Reston, VA 20191-4367.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
D 6487
5. Apparatus 7. Hazards
5.1 Little Joe Offset Color Proof Press , Model H or S. 7.1 Warning—Since solvents may be hazardous to the skin
Integral components include a distribution plate, printing plate, and eyes, wear rubber gloves and safety glasses during cleanup
inking track guides, impression plate, and blanket cylinder to avoid solvent contact with skin and eyes. In case of contact,
(see Fig. 1). The standard printing plate is 100 by 152 mm (4 wash skin with water; flush eyes for 15 min with water and call
by 6 in.). a physician. See supplier’s Material Safety Data Sheets for
5.2 Ink Pipet, or balance accurate to 0.001 g ink. further information on each solvent used.
5.3 Torque Screw Driver. 7.2 Equipment Cautions—Avoid any operation that will
5.4 Ink Knives. scratch the metal distribution and printing plates or damage the
5,6
5.5 Brayer , with a 63.5-mm (2 ⁄2-in.) diameter and rubber blanket on the impression cylinder.
152-mm (6-in.) length.
8. Procedure for Dry Offset Printing
5.6 Standard Daylight, preferablyaD50 light source
8.1 Prepare the Little Joe Offset Proofing Press as described
conforming to ANSI Standard PH 2.30.
in Annex A1.
5.7 Reflection Densitometer, (Optional), conforming to
8.2 Clean press with appropriate solvent and lint-free rag or
ANSI Standard PH 2.17, having a set of Status T filters
tissue. Remove lint from blanket and printing plate using a
conforming to ANSI Standard 2.18, and used according to
camel hair brush.
CGATS.4.
8.3 Place guide tracks against printing plate and place a 140
1 1
NOTE 1—The filter systems in typical densitometers are suitable only
by 210-mm (5 ⁄2 by 8 ⁄2-in.) piece of test stock on the
for use with black, white, and the three process colors (yellow, magenta
impression plate.
and cyan).
8.4 Determine the approximate amount of ink that will give
5.8 Spectrophotometer, (Optional), hand-held, calibrated
the proper density. If uncoated stock, start with 0.6 mL or 0.6
according to manufacturer’s instructions and used according to
g of ink. For coated stock, start with 0.4 mL or 0.4 g of ink.
CGATS.5.
8.5 Using an ink knife or a pipet, apply the ink to the brayer
evenly across the roller.
6. Materials
8.6 Roll the ink on the distribution plate with the brayer
6.1 Ink Sample.
until a uniform ink film is created and the entire distribution
6.2 Specification for the target optical density; alternatively,
plate has been used.
a reference print to be matched.
8.7 Once a uniform film exists, roll the brayer from corner
6.3 Printing Substrate such as paper or paperboard cut to
to corner of the ink distribution plate to make a single “X”
1 1
approximately 140 by 210 mm (5 ⁄2 by 8 ⁄2 in.).
pattern. Then move the brayer from top to bottom and bottom
6.4 Solvent, appropriate to ink system.
to top without lifting (2 passes) along the middle of the
6.5 Lint-free Rags or Tissue.
distribution plate. Turn brayer 180° (feet to point in opposite
6.6 Shim Stock, metal or plastic, the same size as the
direction) and repeat“ X” pattern and top to bottom and bottom
printing plate and 0.5, 1, 2, 5 or 10 mils in thickness.
to top motion.
8.8 Apply ink to printing plate with six passes of brayer
using a smooth motion (one pass is motion in one direction
The sole source of supply of the apparatus known to the committee at this time
is Little Joe Industries, Belle Mead, NJ 08502. If you are aware of alternative
only, left to right or right to left). Do not lift brayer between
suppliers, please provide this information to ASTM Headquarters. Your comments
passes. Pressure applied will depend on the ink rheology but
will receive careful consideration at a meeting of the responsible technical
last pass (dressing pass) should be less than the pressure for the
committee , which you may attend.
previous five passes. Push guide tracks away from printing
For printing ultra violet (UV) systems, use a special blanket and brayer
formulated for the purpose.
plate.
FIG. 1 Little Joe Offset Printing Press Model H
D 6487
NOTE 2—For heat-set inks, apply heat or run through the Sinvatrol in
8.9 Repeat 8.7 and 8.8 to ink the brayer and again apply ink
accordance with Test Method D 6073. Energy-curable inks should be run
to the printing plate. Push guide tracks away from printing
through a UV lamp or other appropriate apparatus.
plate.
NOTE 3—For letterpress printing, follow the procedure for dry offset
8.10 Apply ink to the blanket by engaging cylinder, and
printing with the following exceptions: In 8.3, tape or ot
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