Chapter 24
Flood & Stroke Methods And Wet Printing Vs. Flashing
It is very interesting to see how much printers are split on this issue. I learned how to screen print in New York and I had never seen anyone pull their stroke before I moved to Arizona. At first, I thought this was a simple case of west coast vs. east coast styles. But that is not the case and it seems this debate has been going on for some time. Only now has it become more an argument of efficiency and ergonomics rather than personal style or preference.
In the early years of my screen printing experiences, I was limited to a small group of printers who basically came from a similar "school" of screen printing. As I went to college my exposure to different printing methods was expanded. I took many different types of printing classes throughout my college years but screen printing was always closest to me. It was here that I was being instructed to push my flood and pull my stroke.
I was surprised at this technique, because pulling your flood and pushing the stroke seemed so natural to me. The control you have over the ink is so much better. And the way the ink curls and rolls as you push the squeegee toward the print head just feels right. Not to mention pushing with your palms and controlling the angle of your squeegee this way also gives greater control of the ink.
Now I have tried both methods and there are certain print runs that just do not work out the best and I end up adapting my flood and stroke methods anyway. But there are benefits to the pull flood and push stroke.
VIDEO: How Much Squeegee Pressure Is Too Much?
Pull Flood And Push Stroke:
- Much more ink control in the ink well. Ink does not get all over the frame nor does it build up at your end of the screen.
- I believe you can sheer the ink off better with this method giving better coverage and overall print results.
- Using your palms to push is more efficient. It transfers force better.
- You can control the amount of downward force by adjusting your squeegee angle. More of a right angle will force more ink through the mesh.
- Your wrists and fingers will find this method much more comfortable over long print runs. Endurance is greater. You will not tire as easily and it does not abuse your wrists as much.
- The angle of the squeegee against the screen causes the ink to roll toward the print head. With a quick movement of the squeegee handle up with a bit of down force at the end of the stroke will clear excess ink off the blade and make it easy to rest the squeegee without carrying strings or clumps of ink all over the place.
Push Flood And Pull Stroke:
- Ink gets all over the frame and builds up nearest printer making it necessary to pick up the ink with the squeegee and carry it back to the starting point or plainly pushing the ink back and flooding the screen stencil.
- Flooding your stencil by pushing the ink toward the print head with the screen up, increases the possibility of flooding out the stencil completely thus ruining the next print. You must be careful not to push too much ink into the stencil on your flood stroke.
- This method is very abusive and damaging to the wrists and fingers. Arthritis and carpel tunnel syndrome are results of such abuse.
- It looks messy and sloppy to others. To me, it almost makes the whole process look more haphazard than anything.
- This style of printing makes it easy to get ink all over your product and shop.
Remember, there will be many who will want to argue with me about this and ultimately it comes down to what works best for you. I know I am among a minority of printers who prefer the pull flood and push stroke. Everyone is different and likes to work in their way. As far as the physical, endurance, and print quality benefits; I have heard that you can lead an animal to water but you cannot make it drink. To each his own, as it were.
Manual screen printing is riddled with variables and it can often need some finesse. That is why I like to set everything up to start out, the same. I follow all the same methods until an adaptation is demanded by other factors. Screen printing is first a technical skill and secondly an art.
VIDEO: Flood & Stroke Methods
VIDEO: Doing A Print Stroke Without Flooding
Printing Wet And Printing With A Flash Cure
The following is based on manual printing working with textile plastisol inks.
The ability to print wet is determined by two factors. First is the artwork. If you can set your artwork up so that all the registration is butt/butt then you should have no problem printing wet. Butt/butt simply means the edges of 2 different printed colors come edge to edge but do not overlap. This could be done with all the colors including the black printer. Sometimes leaving a small gap between colors can also be beneficial to printing wet on wet.
This creates a very low tolerance registration. That is to say that you will need to be able to register your colors precisely. It would probably be a good idea to have micro registration to do this. But printing wet will be faster in the long run.
The amount of ink you lay down with each print is also something to consider when printing wet. The next screen down will "pickup" a certain amount of ink off the shirt from the previous ink printed. So, we want to print an amount that is not going to cause a problem with the pickup factor. Just enough is best as a general standard.
The pickup of ink onto the back of consecutive screens will ultimately, over the duration of the print run, cause the print quality to suffer. It may appear fuzzy or blurry at the edges at some point. This is simply corrected by wiping down the substrate side of all the screens at certain intervals throughout printing.
There is only one time; I can think of, that you must flash your print before moving to the next no matter what. And that is when you print an under base. An under base is often done when printing colors on dark garments. A layer of white ink is printed under and before all other colors. This allows the colors to stay true and maintain opacity over the dark fabric. When you print an under base, you must flash it before printing the subsequent colors. If you do not, you will have a big muddy mess.
Flashing between prints is often done when the artwork has traps or layering that makes it necessary to print ink on top of ink. I think most printers avoid this type of artwork set up because it is slower than printing wet. It can be time consuming and riddled with variables associated with flashing. However, flashing between all colors will result in a much sharper print where the colors meet.
Sometimes we might want to set the artwork up so that all the colors print wet and then are flashed before finally printing the black. This may be done for various reasons most often dealing with how the black is supposed to look in the final print. It may be that you want the black to overprint for aesthetic reasons.
Either way, you need to assess your end goals of the print run to decide how to print it. This decision may be weighted on the final print aesthetics desired. It may be that the original art dictates how it will be done anyway but for the most part, you should be able to choose to print wet or with a flash.
Remember, artwork is the single most important step to creating an excellent, high quality print. If your artwork is not set up properly for screen printing, not only will the print look bad but the job could be very difficult to print.