ASTM D6688-20

Standard Practice for Relative Resistance of Printed Matter to Liquid Chemicals by a Sandwich Technique

SIGNIFICANCE AND USE
4.1 Many types of printed matter, notably container labels, packaging materials, magazine and book covers, must be resistant to liquid materials that may contact them advertently or inadvertently. This practice permits an assessment of resistance of printed matter to several types of liquids.  
4.2 The requirement that a reference print be run at the same time as the test print minimizes effects of atmospheric conditions (humidity and temperature) and other variations which may develop.  
4.3 This practice can be used to determine whether new formulations are suitable for the end-use purpose and for specification acceptance between producer and user.
SCOPE
1.1 This practice covers the evaluation of the relative resistance of printed matter to liquid chemicals, as evidenced by lack of discoloration, bleeding, or loss of gloss.  
1.2 This practice utilizes a sandwich procedure similar in principle to ISO/TC 130 N 589. Spotting or immersion procedures are covered in Test Methods D1308, D1647, and D2248.  
1.3 This practice is applicable to prints on any flat substrate including paper, paperboard, metallic foil, metal plate, and plastic films, and produced by any printing process including letterpress, offset lithography, flexography, gravure, silk screen, and non-impact.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see Section 7.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-May-2020
• ICS: 87.080 - Inks. Printing inks
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.56 - Printing Inks

Relations

• Replaces: ASTM D6688-11 - Standard Practice for Relative Resistance of Printed Matter to Liquid Chemicals by a Sandwich Technique (Withdrawn 2020)
• Effective Date: 01-Jun-2020
• Refers: ASTM D2248-01a(2018) - Standard Practice for Detergent Resistance of Organic Finishes
• Effective Date: 01-Feb-2018
• Refers: ASTM D2248-01a(2013) - Standard Practice for Detergent Resistance of Organic Finishes
• Effective Date: 01-Jun-2013
• Refers: ASTM D2248-01a(2007) - Standard Practice for Detergent Resistance of Organic Finishes
• Effective Date: 01-Jun-2007
• Refers: ASTM D1308-02(2007) - Standard Test Method for Effect of Household Chemicals on Clear and Pigmented Organic Finishes
• Effective Date: 01-Jun-2007
• Refers: ASTM D1308-02e1 - Standard Test Method for Effect of Household Chemicals on Clear and Pigmented Organic Finishes
• Effective Date: 10-May-2002
• Refers: ASTM D1308-02 - Standard Test Method for Effect of Household Chemicals on Clear and Pigmented Organic Finishes
• Effective Date: 10-May-2002
• Refers: ASTM D2248-01a - Standard Practice for Detergent Resistance of Organic Finishes
• Effective Date: 10-May-2001
• Refers: ASTM D2248-01 - Standard Practice for Detergent Resistance of Organic Finishes
• Effective Date: 10-May-2001
• Refers: ASTM D2248-93 - Standard Practice for Detergent Resistance of Organic Finishes
• Effective Date: 10-May-2001
• Refers: ASTM D1647-89(1996)e1 - Standard Test Methods for Resistance of Dried Films of Varnishes to Water and Alkali (Withdrawn 2004)
• Effective Date: 01-Jan-1996

Overview

ASTM D6688-20 is a widely recognized standard practice for evaluating the relative resistance of printed matter to liquid chemicals using a sandwich technique. Developed by ASTM International, this standard is essential for manufacturers and users of printed materials seeking to assess how resilient printed surfaces are when exposed to various liquid chemicals. Its methodology provides a reliable means of identifying potential issues such as discoloration, bleeding, or loss of gloss, which are critical for maintaining the quality and durability of printed products.

This practice plays an important role in the quality assurance of printed items commonly subjected to liquid exposure, such as container labels, packaging materials, magazine covers, book covers, and other commercial prints. It is applicable to prints on a wide range of flat substrates - including paper, paperboard, metallic foil, metal plate, and plastic films - produced by all major printing processes.

Key Topics

• Assessment of Chemical Resistance: Measures the resistance of printed matter to liquid chemicals, focusing on visible effects like discoloration, ink bleeding, or loss of surface gloss.
• Sandwich Technique: Uses a procedure where the test print and a reference print are each sandwiched between filter paper saturated with the test liquid, simulating real-world liquid exposure.
• Reference Standardization: Mandates the use of a reference print during testing to minimize the influence of environmental factors like humidity and temperature.
• Versatile Substrate Coverage: Suitable for all flat substrates and a variety of printing methods, such as letterpress, offset lithography, flexography, gravure, silk screen, and non-impact prints.
• Quality Control and Specification Acceptance: Facilitates the selection of appropriate formulations for end-use and serves as a specification acceptance tool between producers and users.
• Safety and Compliance: Encourages adherence to safety, health, and environmental practices during test implementation.

Applications

The ASTM D6688-20 standard finds practical value across multiple sectors:

• Packaging and Labeling: Ensures that labels and packaging materials withstand accidental or intentional contact with household chemicals, oils, detergents, and various liquids.
• Publishing Industry: Applied to magazine and book covers to maintain visual quality and prevent ink degradation from consumer handling or spillages.
• Quality Assurance in Printing: Acts as a benchmark test for new ink formulations, substrates, or printing processes before entering full-scale production.
• Specification Acceptance: Assists manufacturers and clients in defining and verifying minimum resistance requirements for printed goods to liquid exposure.
• Research and Development: Supports innovation by allowing testing of new inks or printing technologies under controlled, repeatable conditions.

By using this standard, companies can enhance product durability, comply with contractual quality requirements, and reduce costs associated with product failures or replacements.

Related Standards

Several standards are closely linked to ASTM D6688-20, offering complementary or alternative methods for evaluating print resistance:

• ASTM D1308: Test Method for Effect of Household Chemicals on Clear and Pigmented Organic Finishes.
• ASTM D1647 (Withdrawn): Methods for Resistance of Dried Films of Varnishes to Water and Alkali.
• ASTM D2248: Practice for Detergent Resistance of Organic Finishes.
• ISO/TC 130 N 589: Graphic Technology - Prints and Printing Inks - Assessment of Resistance to Various Agents.

These related documents provide additional guidance on liquid chemical resistance and help organizations develop comprehensive testing protocols for printed materials.

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Keywords: chemical resistance, bleed resistance, printed matter, printing inks, packaging durability, ASTM D6688-20, sandwich technique, quality control, substrate testing

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D6688 − 20
Standard Practice for
Relative Resistance of Printed Matter to Liquid Chemicals
by a Sandwich Technique
This standard is issued under the fixed designation D6688; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D1308Test Method for Effect of Household Chemicals on
Clear and Pigmented Organic Finishes
1.1 This practice covers the evaluation of the relative
D1647Test Methods for Resistance of Dried Films of
resistance of printed matter to liquid chemicals, as evidenced
Varnishes to Water and Alkali (Withdrawn 2004)
by lack of discoloration, bleeding, or loss of gloss.
D2248PracticeforDetergentResistanceofOrganicFinishes
1.2 This practice utilizes a sandwich procedure similar in
2.2 Other Standards:
principle to ISO/TC 130 N 589. Spotting or immersion
ISO/TC 130 N 589Graphic Technology-Prints and Printing
procedures are covered in Test Methods D1308, D1647, and
Inks-Assessment of Resistance to Various Agents
D2248.
3. Summary of Practice
1.3 This practice is applicable to prints on any flat substrate
including paper, paperboard, metallic foil, metal plate, and
3.1 Prints of the test and reference printing inks are each
plastic films, and produced by any printing process including
sandwichedbetweenfilterpaper,whichhasbeensaturatedwith
letterpress,offsetlithography,flexography,gravure,silkscreen,
the specified liquid. After the agreed upon contact times, the
and non-impact.
prints and filter paper are dried and then examined for
1.4 The values stated in SI units are to be regarded as objectionable changes such as discoloration, bleeding, or loss
in gloss. The test print is then rated as better, equal, or worse
standard. No other units of measurement are included in this
than the reference print.
standard.
1.5 This standard does not purport to address all of the
4. Significance and Use
safety concerns, if any, associated with its use. It is the
4.1 Many types of printed matter, notably container labels,
responsibility of the user of this standard to establish appro-
packaging materials, magazine and book covers, must be
priate safety, health, and environmental practices and deter-
resistant to liquid materials that may contact them advertently
mine the applicability of regulatory limitations prior to use.
or inadvertently. This practice permits an assessment of resis-
For specific hazard statements, see Section 7.
tance of printed matter to several types of liquids.
1.6 This international standard was developed in accor-
dance with internationally recognized principles on standard-
4.2 Therequirementthatareferenceprintberunatthesame
ization established in the Decision on Principles for the
time as the test print minimizes effects of atmospheric condi-
Development of International Standards, Guides and Recom-
tions (humidity and temperature) and other variations which
mendations issued by the World Trade Organization Technical
may develop.
Barriers to Trade (TBT) Committee.
4.3 This practice can be used to determine whether new
formulations are suitable for the end-use purpose and for
2. Referenced Documents
specification acceptance between producer and user.
2.1 ASTM Standards:
5. Apparatus
5.1 Glass Plates, 60 by 90 mm, two for each printed
This practice is under the jurisdiction of ASTM Committee D01 on Paint and
specimen (minimum four per test).
Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.56 on Printing Inks.
5.2 Petri Dish, at least 100 mm in diameter.
Current edition approved June 1, 2020. Published June 2020. Originally
approvedin2001.Lastpreviouseditionapprovedin2011asD6688–11whichwas
withdrawn January 2020 and reinstated in June 2020. DOI: 10.1520/D6688-20.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or The last approved version of this historical standard is referenced on
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM www.astm.org.
Standards volume information, refer to the standard’s Document Summary page on Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 4th Floor, New York, NY 10036, http://www.ansi.org.
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D6688 − 20
5.3 Weight, 1 kg. 8.4 Unlessotherwisespecified,atleasttwospecimensareto
be run with each test liquid.
5.4 Timer, calibrated in minutes up to 24 h.
9. Procedure
5.5 Oven, capable of maintaining 50°C.
9.1 Unless otherwise specified, conduct tests at 23 6 2°C.
6. Materials
9.2 Pour a quantity of the test liquid into a petri dish.
6.1 ReferencePrint,ofknownresistancetothespecifiedtest
9.3 Take four pieces of filter paper marked T and using
liquid, cut to 20 × 50 mm and marked with R.
forceps, immerse them completely in the liquid. Remove and
6.2 Filter Paper, white neutral for qualitative analysis, with
drain until no f
...