Choosing the Right Inks for Shirt Materials

posted by Melissa Crawford - Texsource - 5/20/2017

I have a shirt made out of Exotic Space Martian Silk - what is the best ink to use for this?

While this isn't exactly a question we get every day here at Texsource, it does help illustrate the point that many people (especially those who may be new to the screen printing process) have questions about exactly which type of ink to use for a certain type of shirt material (or 'substrate').  I am going to attempt to clear the smoke from the subject and bring things into focus!

COTTON
Ah, the granddaddy of them all, cotton is by far the most common material for tshirts.  It is a light, durable, soft, and economical fabric that is versatile to printing / coloring.  There are also sub-settings for cotton such as combed cotton, organic cotton, pima/supima cotton, and slub cotton.  Most of these sub categories have to do with the length of the fibers or how the fabric is woven.  In the case of organic cotton, it is different mostly in how it is grown, harvested, and processed in a more environmentally aware method.  The difference in these can be felt by the hand as either softer or more textured than other types.  Combed cotton uses a process in manufacturing that causes it to have a smoother feel than other types.

INKS TO USE
Most any general purpose ink will work well with any cotton fabric.  This would be the Texsource GEN Series inks, the Union Maxopake inks, the International Coatings 700 series inks, or the Triangle 1100 Multipurpose series inks.

LINEN
Like cotton, linen is grown and processed, in this case from the flax plant.  It is lightweight, moisture wicking, and has a textured weave feel.  Linen is durable, but gets softer with multiple washings.  It is an easy fabric to print, but can wrinkle more easily which may require more frequent ironing.


INKS TO USE
Same as cotton, most general purpose inks will work well with linen fabrics.  Mesh counts may need to be adjusted and some detail may be lost as linen has a tendency to be woven more 'loosely' than cotton.

POLYESTER
An entire series of articles could be written just on printing polyester shirts.  In short, polyester is a synthetic material that many still associate with the flamboyant disco fashions of the 70s.  It gained popularity as a material that could be washed, pulled, worn, and generally could take all kinds of abuse yet still maintain a smooth, wrinkle-free appearance.  It does not mold or mildew and is resistant to shrinking or stretching.  It is often seen in athletic apparel.  Polyester is often a trouble fabric for many screen printers because polyester must be sublimated or dyed to have any color.  That is, a green polyester shirt has been 'dyed' green in a heating or dyeing process.  When screen printing, the temperature that you need to cure your ink in the dryer is often higher than the material can hold its dye at.  Such a temperature will cause the polyester to 'release' the dye, which can cause a problem known as dye migration.  This is when the color of the shirt 'bleeds' into the color you printed.  To prevent this, you can use a 'blocker'-type ink as an underbase (a light grey is usually the best choice, but others use simply white).  You can then more safely print your colors without the fear of such dye migration issues.

More recently a relatively new type of ink, silicone ink, has been introduced that specifically combats this problem.  Silicone inks can typically cure fully at a much lower temperature than standard plastisol (around 260-270 degrees rather than 300-320).  This is often lower than the dye release point on most quality polyester materials thus eliminating dye migration issues.  Silicone ink has a very soft feel (called 'hand') and is extremely flexible, virtually eliminating cracking.  It is becoming a very in-demand ink for athletic uniforms.

INKS TO USE
Use a good underbase such as International Coatings Guardian Gray or Blocker Gray.  For ink, consider Texsource Poly inks, Union Poly inks, International Coatings 7100 series inks, or Triangle 1700 Low Bleed series inks.  If considering some of the new silicone ink products, try Rutland Silextreme inks.

LYCRA / SPANDEX
It may have seen its heyday among the slew of 80s heavy metal rockers, but lycra (spandex) has seen new life more recently as athletic wear such as yoga pants and tops, swimwear, and even casual shirts / tops.  It has found a home in athletic wear mainly due to its ability to easily stretch greatly while being resistant to wrinkles.  As lycra has great stretchability, a stretch additive is recommended.


INKS TO USE
General purpose inks will serve you well on most lycra/spandex substrates, but you will need a stretch ink additive such as the Union Unistretch 9160.  When printing a white color on pure black lycra, you may get better results using a poly white ink such as the Rutland Super Poly White ink or International Coatings 7113 Athletic White ink.

RAYON
Rayon is made from purified cellulose, mainly from wood pulp.  Because it is chemically converted into a compound, it is considered a semi-synthetic fiber.  It is well known as a popular replacement for silk.  When woven or knitted it is a silky, breathable fabric common in athletic wear.  Rayon does not hold up as well to prolonged wear and can more easily wrinkle.

INKS TO USE
Because Rayon is a semi-synthetic material, you may find some testing is necessary for best printing.  Much will depend on the percentage of rayon in the material.  If adhesion is an issue, you may want to add a catalyst such as Union Nylobond or International Coatings Nylon Bonding Agent.  On materials that use less rayon, you may use most general purpose plastisol inks.  Like lycra, you may want to test using poly inks when printing on darker colors.

NYLON
Nylon is a fully synthetic material that has found many uses in other applications including plastics, flooring, automotive, films, and more.  It is popular in shirt material for its excellent resistance to heat, is lightweight, and wrinkle resistant.  It also blends well with other materials.  Nylon is more prone to shrinking and is not as stain tolerant as other materials.  When using inks to print on nylon materials, a 'catalyst' should be mixed with the ink.  A catalyst works as a adhesive agent, particularly for extremely smooth surfaces.  When mixed properly, your ink / catalyst mixture will cure as normal and will be very resistant to peeling.


INKS TO USE
For a catalyst, use the International Coatings Nylon Bonding Agent, or the Union Nylobond catalyst as described in the inks for rayon shirts.  General purpose inks can be used on most colors, but light colors on dark fabrics may benefit from using low bleed poly inks.

BLENDS
Many shirts today are blended fabrics, sometimes with two, three, or four fabric types.   The most common you are likely to see as a screen printer would be the cotton polyester blend fabric.  Here is where some testing may be required as blends may be 50/50 or any other ratio.  Typically, general purpose inks may do well for most color fabrics, but as with 100% polyester shirts some dye migration or bleeding may occur, at which point you may want to consider a blocker underbase and / or poly inks.


INKS TO USE
Test using a combination of blocker inks such as International Coatings Guardian Gray or Blocker Gray.  Your general purpose inks such as Texsource GEN inks, the Union Maxopake inks, the International Coatings 700 series inks, or the Triangle 1100 Multipurpose series inks.  For poly ink, consider Texsource Poly inks, Union Poly inks, International Coatings 7100 series inks, or Triangle 1700 Low Bleed series.

CONCLUSION
While this certainly isn't a complete listing of available materials that you might see in your screen printing shop, it is a list of the more common types you may encounter.  As always, testing is the key; get the first shirt right and approved before you begin your batch.  Taking shortcuts in the screen printing process can lead to lost customers and lost profits.  Experimentation can often lead to creative and valuable results, and this guide should serve as a great base from which to start your screen printing journey.  If you are looking for where to find some of these great screen printing inks and more, look no further than the Ink section on the Texsource website - all the screen printing supplies you need and every product mentioned in this article can be found right there, in stock, ready to go!  #printlife