What is Underbase Printing?
This is a bottom layer of ink used to optimize the brilliance and quality of a print. The most common under base used is the main white ink that a shop is using, and it is most commonly used on darker garments in order to deliver the quality of colors the job needs. There are other ways to print an under base, but this lesson will be focusing on using white ink to achieve a quality print.
Why use an underbase?
Well, have you ever tried printing a red ink on a black shirt and wonder why it appeared to be "off looking" or "flat?" Most printers have gone through this as well. Under basing takes that "flat" look and turns into a "popping" look. This process enables you to give a better looking product to your customers that will have them coming back to you for future orders. Yes, an under base on a shirt will cause a thicker print on a garment, but the trade off is a much better print and much better satisfaction in your customers.
What Inks Should I Use?
When using a white as an under base, choose a white that is smooth, soft, and high in opacity. This will allow for the best result while the other inks are being printing on top. As far as the other colors, using a medium opacity ink like the Texsource GEN Series would be ideal. Texsource Prime Time, Texsource White Dream, and Texsource Odyssey White are great for cotton and cotton/poly blend garments. Rutland Super Poly White and Triangle 1706 are great for Polyester garments.
Tips for Underbase Printing Printing:
A great under base will result in a great finished product, whereas, a bad under base will result in a bad finished product. The first layer of ink laid down will need to be smooth and consistent in order to be successful. This may require a double stroke on the white or a print, flash, print before moving onto the other colors. Each garment reacts different to a stroke of white causing for the printer to need to know his/her inks and his/her garments for the best results.
Trap It! Choke It!
It is very often that customers have issues registrating an image that requires an under base. The best way to resolve this issue is not necessarily on the press, but rather, in the artwork. There are two different methods that can be used to help registrate an image properly. Option one is to choke the under base by 1 point. Choking the under base simply causes it to be slightly smaller than the inks that print on top. This will allow for the white ink to "disappear" when the print is complete. The second option is to trap the ink on top by 1 point. This process causes the image on top to be slightly bigger than the under base causing it also to "disappear."
The most common mesh counts for the under base white are a 110 and a 160. This allows for a solid and smooth image area for the other inks to print on. Higher mesh counts can result in a less desired look to the finished product because it will not allow a good base for the primary colors. Because printing on top of an under base is like printing on plastic, a higher mesh count will be needed for the colors going on top. Anywhere from a 200 to a 305 depending on the detail needed