Mistakes happen, such is the human existence—are we getting too deep for a printer’s blog? Maybe.
But alas, no one is perfect (try as we might), and no process is 100% without a chance for error. This truth applies in printing as it does in other areas of life.
“Mistakes” in printing could be the result of one wrong decision or a combination of factors, whether that be with paper selection, an oversight or error in file preparation, a defect in the manufacturing of ink or paper, or it could just be an accident of chance.
Let’s look at what could happen and, when possible, how to avoid it.
Gas Ghosting
(1) Phenomenon of a faint image appearing on a printed sheet where it was not intended to appear. Chemical ghosting refers to the transfer of the faint image from the front of one sheet to the back of another sheet.***
Also known as gloss ghosting. A condition occurring during the printing process when vapors from drying ink on one side of a press sheet interact chemically with dry ink or blank paper on sheets in contact with or on the reverse side of the same sheet creating unintended faint images.****
Allowing enough drying time between each process is critical to avoid possible occurrences of gas ghosting, so best to provide ample time in your schedule whenever possible.
Mottle
Spotty, uneven ink absorption mostly in solid areas. Also called sinkage.*
If you have large areas of solid color in your design, it is possible the printed piece will have a mottled appearance. This is often a result of low quality paper, poor ink formulation or a combination of the two factors. It can also be due to conditions during print, such as pressure and temperature. Mottling can be diminished or avoided by adjusting pressure and temperature, or by using higher quality paper and ink.
If your design and budget allow, using a double hit of a PMS color for solid areas can help even out an occurrence of mottling. This is also called a kicker plate, and you can ask for it to be factored into your pricing when quoting your print project.
Picking
When the tack of ink is stronger than the surface strength of the paper, some lifting of the paper surface occurs; this is referred to as picking. Or, an occurrence in printing whereby the tack of ink pulls fibers or coating off the paper surface, leaving spots on the printed surface.**
The use of press powder to assist in drying during a run is critical in avoiding any picking issues.
Overprinting
To print one image or color over a previously printed image or color, such as printing type over a screen tint. Also called surprint.*
Overprinting in and of itself is not a mistake. Black type over a background is usually set to overprint to avoid needing trap around each letter. Overprinting becomes an issue when a wrong setting is selected, or unselected, and not caught, and an undesired effect results.
Show Through
When the printing on one side of a sheet is seen from the other side, a frequent problem with thin papers.****
If your design has heavy coverage and show through is a concern, it’s best to err on the side of a heavier weight stock if the piece allows it. Otherwise, be aware that you might be able to see the ink from the other side of the sheet. If you’re unsure of what weight or finish to go with based on your design (imagery and construction), check with your printer for suggestions!
SOURCES
* https://specialtyprintcomm.com/blog/glossary-print-terms/
** https://www.minutemanteam.com/resources/glossary.html
*** https://www.printindustry.com/glossary.aspx
**** https://modernlitho.com/2020/08/printing-term-dictionary/
Photo by Samuel Regan-Asante on Unsplash