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18May/15Off

Is all inkjet ink created equal? A closer look at a popular dyebased ink from eBay.

IMG_8518Several months ago, our tech support staff was contacted by a local customer who had purchased a set of our aftermarket refillable Epson 1400/1430 cartridges to use with aftermarket dye based ink which he had purchased from a popular eBay seller.  The customer was having issues with clogged nozzles and ink drips on prints, which he felt might be issues with our cartridges.  As our techs worked to diagnose the problem the customer was having, other issues that could not be cartridge related, such as poor dry times, were added to the list of deficiencies.  After our techs failed to find any issues with the cartridges themselves, the customer purchased a set of our D2 inks and drained/refilled the cartridges.  After refilling the cartridges, the printer began to function normally.

These types of issues occur quite often in our industry,as the quality of ink is something that the average user has neither the equipment nor the knowledge to test.  In an attempt to get useful data for comparison and troubleshooting, we brought in 3 sets of dye ink from the eBay supplier (ND) to run some comparison tests.  In our testing, we compared our Inksupply.com D2 Claria compatible ink, ND Claria compatible ink, and OEM Epson Claria Ink.

When testing inks, our first test is typically a drawdown on HDPE (High Density Polyethylene), a non-porous plastic.  This test gives us a very fast indication of whether the ink’s surface tension is in the correct zone. We start here because many low quality imported inks will immediately fail this test, and further testing is really unnecessary.  We have included a video of a drawdown to illustrate how visual data obtained from this test quickly reveals ink characteristics that could lead to printing problems.

Video Here

Even though the ND inks did not pass this drawdown test, we decided to continue with the physical properties tests to obtain concrete numbers to compare the properties of this ink to our Inksupply D2 and OEM Epson Claria inks.  Our physical properties tests include density, conductivity, pH, surface tension and viscosity tests.  These are some of the standard tests we use in-house for batch evaluation and quality control. We are in the process of conducting fade and color testing. An explanation of each test is available at the end of this post.

Testing Methodology
To reduce testing time, number of variables to display, and because of the similarity of the light inks to their full strength counterparts, we are only testing the Cyan, Magenta, Yellow and Black inks from each supplier. We obtained one sample of each color (CMYK) from ND, Epson (from OEM cartridges), and D2 pulled from our stock.  Each test was run 3 times and the results were averaged.  As we only had one sample of each ink our results are only representative of one batch from each supplier; however, these are batches that were available for sale to customers and should therefore be within each company's specs.

Test #1 - Denisty
Our density tests were exactly as expected, with the values being essentially equal.
Brand
Cyan
Magenta
Yellow
Black
Inksupply D2
1.06 g/cm3
1.06 g/cm3
1.06 g/cm3
1.06 g/cm3
ND Claria Compatible
1.05 g/cm3
1.05 g/cm3
1.05 g/cm3
1.05 g/cm3
OEM Epson Clara
1.06 g/cm3
1.06 g/cm3
1.06 g/cm3
1.06 g/cm3
Test #2 - Conductivity

With lower conductivity being better, this test is a win for Epson; however, the OEM Claria inks use a proprietary dye that helps to boost fade resistance and has a lower natural conductivity.  We have tested inks from many suppliers over the years, as well as Epson’s Photo Dyes and have found that values of less than 3.00 mS/cm are typical and have no impact on printing quality or function.
Brand
Cyan
Magenta
Yellow
Black
Inksupply D2
1.36 mS/cm
1.24 mS/cm
2.87 mS/cm
1.93 mS/cm
ND Claria Compatible
1.00 mS/cm
1.41 mS/cm
3.94 mS/cm
2.82 mS/cm
OEM Epson Claria
0.32 mS/cm
0.67 mS/cm
2.91 mS/cm
1.24 mS/cm
Test #3 - pH
Most dyebase inks end up being acidic at the end of production (as a result of the dyes) and require that a pH buffer be added to increase the pH into an acceptable range.  During the life of the ink, a small amount of pH decrease is expected, so being closer to the upper end of the tolerance is desirable.  While Epson does not publish their specs, every sample we have tested from OEM cartridges has had a pH of 8.5-9.0, while the aftermarket industry acceptable range is typically 7.0-9.0.  ND publishes their pH range as 6.0-8.0, and Inksupply D2 inks are buffered to 8.0-9.0
The pH test results for ND's Claria Compatible inks are worrisome, as pH levels lower than 6.0 can quickly ruin a printhead.
Brand
Cyan
Magenta
Yellow
Black
Inksupply D2
9.0
8.8
9.0
9.0
ND Claria Compatible
5.2
5.4
6.4
5.5
OEM Epson Claria
8.8
9.0
9.0
9.0
Test #4 - Surface Tension
Surface tension plays a big role in the overall performance of inkjet inks.  High resolution color inkjet printing relies on combinations of closely packed CMYK dots with an inkjet receptive media (paper) working together to produce millions of colors.  Photo paper manufacturers use specialized coatings on their paper that provide the environment needed to produce high resolution images, and they make assumptions about the pH, surface tension and viscosity of the inks that will be used.  Values outside of the expected range can produce prints that have poor resolution and color.  The acceptable range for Inksupply D2 is 24-27 dynes/cm, Epson and ND do not post their tolerances.
Brand
Cyan
Magenta
Yellow
Black
Inksupply D2
24.7 dynes/cm
25.3 dynes/cm
24.1 dynes/cm
26.7 dynes/cm
ND Claria Compatible
36.5 dynes/cm
37.0 dynes/cm
37.0 dynes/cm
37.3 dynes/cm
OEM Epson Claria
26.3 dynes/cm
25.9 dynes/cm
26.6 dynes/cm
26.3 dynes/cm
Test #5 - Viscosity
The viscosity of aqueous dyebase inks is typically adjusted with the addition of humectants (typically glycols like glycerin, triethylene glycol, diethylene glycol, etc.).  These humectants allow the formulator to control decap time (time it take for the ink to dry in the printhead), print dry time, droplet characteristics, as well as the ink's ability to flow through the printhead.  The quality, quantity, and type of humectants is a balancing act, as customers desire fast dry times of prints but don’t want to deal with clogged nozzles due to ink drying in the printhead.  The acceptable range for Inksupply D2 is 2.3-2.6 cP, Epson and ND do not post their tolerances.
Brand
Cyan
Magenta
Yellow
Black
Inksupply D2
2.5 cP
2.4 cP
2.4 cP
2.5 cP
ND Claria Compatible
2.0 cP
2.0 cP
2.0 cP
1.9 cP
OEM Epson Claria
2.4 cP
2.4 cP
2.3 cP
2.4 cP
Notes
We received 3 different inksets from ND (Epson T273xl set, Epson T277xl set and a dye set listed as a replacement for DuraBrite pigment inks). ND specifically states that the inks they sell are not generic. Though it would be reasonable to expect the T273xl and T277xl to be identical, our testing suggests no difference between all three inksets. We skipped filtration testing, as Epson and Inksupply final filtration is sub 0.5um, and ND’s listed filtration of 0.2nm (0.0002um or roughly twice the width of a Helium atom) is most likely a typo, and we will assume they meant 0.2um.  While the inks are listed as “US made”, their physical properties are remarkably close and the product packaging identical to inks imported from Print Center in Guangdong, China.

Conclusion
While we test products from many competitors each year, we have never published our results.  Most of the products that are dangerously bad for printheads have traditionally been imported and required the customer to purchase them directly from the source overseas.  Unfortunately, as more people turn to big name sites such as eBay.com and Amazon.com for purchases, low quality inkjet products are more readily available, and many customers purchase these products, associating their purchase with the big name site rather than the actual product supplier. Sellers of these products rely on the fact that most users who buy low cost alternatives are not surprised if they fail and do not tend to post negative reviews or give negative feedback.  Add to this the norm of leaving feedback on sites like eBay.com immediately upon receipt of an order instead of after use of a product, and it becomes very difficult to accurately determine whether a supplier is trustworthy.  We urge users looking to save money on their prints by purchasing aftermarket inkjet products to find manufacturers and resellers that have experience in the inkjet industry, and either manufacture or work closely with the manufacturer of their inks.

Glossary
Density - Density is a measurement of mass per unit volume, or the weight per volume, of a sample.  The density of the ink is typically slightly above 1.0 g/cm3 as most dyebase inks have a high water content with lesser amounts of colorants, humectants, surfactants, etc..  The density is also used in the calculations for some tests (e.g. surface tension).
Conductivity - Conductivity is a measurement of the quantity of metal salts in the ink and helps determine purity.  Dyes usually contain sodium salts (NaCl and Na2O4S) which increase the inks conductivity.  Significant amounts of these salts can cause them to precipitate from the ink and clog nozzles.
pH - The acidity or alkalinity of the ink. The pH scale ranges from 0 to 14 with 7 being neutral, numbers less than 7 being acidic, and numbers greater than 7 being alkaline.  If inks are too acidic or to alkaline, they can permanently damage the printhead.  Epson printheads are typically designed for a target pH of 7-9, or slightly alkaline.
Surface Tension - The energy needed to increase the surface area of the ink.  Surface tension helps control drop size, substrate penetration, and dot gain.  If the surface tension is too high, the ink droplets will not spread enough resolution in poor dot gain and underbanding, with images appearing too light.  Too low of a surface tension causes excessive bleed and overbanding with a loss of resolution.
Viscosity - The ink's resistance to flow, sometimes perceived as the “thickness” of the ink. Viscosity helps control droplet size, as well as flow through the printhead.  If the viscosity is too high, the ink may not flow through the printhead, where low viscosity can cause the ink to leak through the printhead.  Improper viscosity can also reduce final image resolution by allowing the droplets to break up before reaching the paper.

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