Somebody showed me a shirt and asked what caused all sorts of problems with the print.
What we see:
- Filled in negative space
- Registration problems including white underprint showing where it should not
- Blurry image
- “Bumpy” print, not smooth
- White ink turned pink
What is causing all these problems?
So what are the causes? Some ink detective work leads to the following conclusion:
All of this is caused by poor screen tension and possibly a warped screen. How so?
- Filled in negative space: This filling in is because if you have poor screen tension you can’t control off contact and too much ink goes down and it fills in the type.
- Registration problems including white underprint showing where it should not: When you have poor screen tension the mesh will drag with the squeegee and that moves the image and causes it not to land on top of the underprint.
- Blurry image: With poor tension you can hold good detail and you get fuzziness on the edges of the images.
- “Bumpy” print, not smooth: With poor screen tension the screen will not release after the print stroke and it pulls the ink up as the screen lifts causing “bumps” and lack of smoothness.
- White ink turned pink: Normally ink turning another color is caused by dye migration. Why not here? The pink color is not universally in all of the white. Also I asked and the shirts are cotton and of a brand not known to have dye issues. My conclusion is that the above other problems caused the printer to have to repeatedly clean the back of the screen, with bad build up on the back of the screen being another function of poor screen tension. As you clean the red screen not thoroughly a thin film of red then contaminates the white print.
I’m not a believer in crazy high tension for screens but I”m guessing this is very low tension or non-existent tension and that is a big problem.