ASTM D3359 Tape Test
Key Takeaways
- ASTM D3359 rates adhesion by cutting through the coating and pulling pressure-sensitive tape off it. It is fast, qualitative and sensitive to how the operator cuts, applies and pulls.
- Method A (X-cut) is for the field and thicker coatings; Method B (cross-hatch lattice) is for the laboratory and films under about 125 µm (5 mils).
- The tape is part of the method. The originally specified 3M Scotch 610 was discontinued, and results obtained with different tapes are not comparable.
- A 5B result proves the coating survived this tape today. It says nothing about durability, so pair it with abrasion, humidity or aged-adhesion testing.
ASTM D3359 Tape Test
ASTM D3359, Standard Test Methods for Rating Adhesion by Tape Test, is a procedure for assessing how well a coating film adheres to its substrate by cutting through the film, applying and removing pressure-sensitive tape over the cuts, and rating the amount of coating removed on a 0 to 5 scale. It was written for paint on metal but is used across the plastics industry as the everyday check for inks, coatings and decorative finishes on molded parts and films, largely because it needs nothing more than a blade, a rule, a roll of tape and a reference chart.
Its popularity is also its weakness. The test is qualitative, the cut and the pull are done by hand, and the tape itself is an uncontrolled variable unless it is specified and recorded. Used with that understanding it is an excellent screening tool; used as a pass/fail specification without stating the tape and the method, it produces arguments between supplier and customer that neither can win.
The Two Methods
Method A: X-cut
Two cuts about 40 mm long are made through the coating to the substrate, intersecting near their middles at an angle of 30 to 45 degrees. Tape is applied over the intersection, smoothed down, and pulled off. The result is rated from 5A (no peeling or removal) down to 0A (removal beyond the area of the X). Method A is intended for coatings thicker than about 125 µm (5 mils) and for field use, where cutting a precise lattice is impractical.
Method B: cross-hatch lattice
A lattice of six or eleven parallel cuts is made in each direction, producing a grid of small squares. Cut spacing depends on dry film thickness: 1 mm for films up to about 50 µm (2 mils) and 2 mm for films between 50 and 125 µm. Coatings thicker than 125 µm should be tested by Method A instead. After the tape pull the lattice is inspected and rated:
| Rating | Coating removed | What it looks like |
|---|---|---|
| 5B | None | Edges of the cuts completely smooth; no squares detached |
| 4B | Less than 5% | Small flakes detached at intersections |
| 3B | 5 to 15% | Flaking along edges and at intersections |
| 2B | 15 to 35% | Flaking along edges and on parts of squares |
| 1B | 35 to 65% | Large ribbons and whole squares detached |
| 0B | More than 65% | Most of the lattice removed |
Procedure Details That Change the Result
- The cut must reach the substrate. A dull blade or a shallow cut leaves the coating continuous under the lattice and inflates the rating. On plastics the opposite error also matters: gouging into a soft substrate creates stress and starts cracks that have nothing to do with adhesion.
- Tape application. The tape is centered over the cuts, smoothed by finger and then rubbed firmly with a pencil eraser or similar to ensure full contact. Trapped air or an unrubbed area gives a soft pull and a false pass.
- Dwell and removal. The standard calls for the tape to be removed within a short window after application (about 90 seconds), pulled rapidly back on itself at an angle as close to 180 degrees as possible. A slow peel or a low angle reduces the stress on the coating and again inflates the rating.
- Inspection. Ratings are assigned by comparison with the reference illustrations in the standard under good illumination, and ideally by an operator who does not know which sample is which.
- Reporting. Method, dry film thickness, tape brand and product, number of replicates and the rating for each. A rating without the tape named beside it is incomplete.
Which Tape: 3M 610, 600 or 810
Earlier editions of the standard named a specific product: 3M Scotch 610, a 25 mm wide semi-transparent pressure-sensitive tape. When 3M discontinued 610, Permacel P-99 became the widely used substitute and was referenced in its turn; it too is no longer produced. Current editions of D3359 no longer tie the method to a single product. The tape is to be agreed between the parties and reported with the result, and the standard is explicit that adhesion strength varies between tapes, so results obtained with different tapes cannot be compared.
In practice three tapes account for most of what laboratories actually use:
- 3M Scotch 600, a clear, glossy general-purpose tape, is the common current choice for formal D3359 work and is generally the most aggressive of the three.
- 3M Scotch Magic 810, the matte “invisible” tape found on every desk, is widely used for informal ink adhesion checks on the production floor. Its adhesion is generally lower than 600, so a coating that passes with 810 has not necessarily passed with 600.
- Discontinued 610 still appears in older specifications and work instructions. A specification that calls for 610 should be updated to name a tape that can be bought, together with correlation data if historical results are to be carried forward.
The point is not that one tape is correct. It is that the tape is a test parameter, exactly like cut spacing, and a result is only meaningful next to it.
Using D3359 on Plastics and Printed Inks
On molded parts and films the tape test is usually a check on pretreatment as much as on the coating. A part that rates 0B or 1B with whole squares lifting cleanly from the substrate has an interface problem: low surface energy, contamination, mold release, additive bloom or a weak boundary layer. That is an adhesive failure, and the remedy is upstream, in surface pretreatment or cleaning, not in the ink. Flaking confined to the cut edges and intersections points instead to a brittle or overcured film failing cohesively at the stress concentration the blade created. The distinction between adhesive and cohesive failure is covered in our guide to why adhesive bonds fail on plastics.
Two further points apply to printed plastics. First, inks are commonly tested immediately after printing and again after full cure and after environmental exposure, because UV-cured and two-part inks continue to develop or lose adhesion for hours to days. Second, for printed flexible packaging ASTM F2252 describes a tape practice written specifically for inks on flexible substrates, and is often the more appropriate reference. Where a number rather than a rating is required, pull-off adhesion by ASTM D4541 or a lap-shear specimen replaces the tape test; the trade-offs are discussed in Techniques for Measuring Adhesion and Abrasion Durability of Coatings and Inks.
Interpreting a Result
Production specifications for inks and decorative coatings on plastics commonly call for 4B or better, with 5B expected on well-pretreated surfaces. Treat the rating as a screen: a 5B today tells you the coating is bonded now, under this tape, at this temperature. It does not tell you what happens after 500 hours of humidity, a dishwasher cycle or a year in a car interior. Pair the tape test with the abrasion, chemical and environmental tests the application actually sees, and use it during development to compare pretreatments side by side, where its speed is a genuine advantage.
Related Terms and Reading
- Techniques for measuring adhesion and abrasion durability of coatings and inks
- Surface energy
- Contact angle
- Adhesive bond failures on plastics
- Inkjet printing on plastics
Applying this in production
The Sabreen Group provides independent engineering support for ink and coating adhesion on plastics, from pretreatment selection to test-method specification and failure analysis. If you are writing an adhesion specification, qualifying a pretreatment or investigating a field failure, our engineering services team can help. Contact us to discuss your application.
Frequently Asked Questions
What is the ASTM D3359 tape test?
A standard method for rating the adhesion of a coating by cutting through it to the substrate, applying pressure-sensitive tape over the cuts, pulling the tape off and rating the amount of coating removed on a 0 to 5 scale. It is quick and qualitative, and widely used for inks and coatings on plastics.
What tape does ASTM D3359 specify?
Historically 3M Scotch 610, later Permacel P-99, both now discontinued. Current editions require the parties to agree on a tape and report it with the result, because adhesion differs between tapes and results are not comparable across them. 3M 600 is the common formal choice; 810 Magic Tape is common for informal checks.
What is the difference between Method A and Method B?
Method A uses a single X-cut and is intended for field use and coatings thicker than about 125 µm. Method B uses a cross-hatch lattice with 1 mm or 2 mm spacing and is intended for laboratory testing of thinner films.
What does a 5B rating mean?
No coating was removed and the edges of the cuts are completely smooth. 4B allows detachment of small flakes at the intersections, below 5% of the lattice area. Most production specifications for inks on plastics call for 4B or better.
Is a tape test enough to qualify an ink or coating?
No. It confirms adhesion at the moment of testing under one tape. Durability against abrasion, chemicals, humidity and heat has to be tested separately, and where a quantitative value is required a pull-off or lap-shear method is used instead.
