Overprint with laser a inkjet print and vice versa

Question

I would like if that's possible to overprint an inkjet print with a laser one in order to put a toner only in some areas and process this multi layered paper with additional finishing after.

I've already read this:

Most inkjet papers have a special coating on them to help the paper absorb the right amount of ink. If the ink is allowed to sink too far into the paper it can “feather” or spread out, making the image look fuzzy. High quality inkjet paper are coated to keep the ink at an optimal level for crisp, clean prints from an inkjet printer. This very coating that helps your inkjet prints come out clean and sharp keeps laser toner from adhering to the paper.

Laser printers don’t use ink to print, they use toner. The toner is rolled onto a drum then heated and applied to the paper where it melts to form your document. If the coating is slick enough the toner just wont stick very well to the coated inkjet paper. Watch out! The inkjet paper coating can also melt in the laser printer which can damage your laser printer. Some of the coatings have polyester properties that can melt in the heat of the laser printer. The melting coating can damage the laser printer’s fuser, drums, and many other parts of the printer.

These parts are costly to fix and some parts of your printer may be beyond all repair which will result in you having to purchase a whole new printer. These warnings are not only for matte inkjet papers but for glossy papers as well. Using glossy inkjet paper in a laser printer can be worse than using matte inkjet paper in a laser printer because the glossy paper usually has more coating than the matte papers.

source: https://pcforms.com/diy-printing-blog/can-you-use-inkjet-paper-in-a-laser-printer/

Now I'm not considering Inkjet Coated Papers, but normal uncoated papers usable technically both by inkjet and lasers.

My questions are:

1. Could an Inkjet printer be ruined by the presence of toner on the paper surface? Can an inkjet printer overprint safely a laser print with also a thick toner density ?

2. Could a Laser printer be ruined by the presence of inkjet ink on the paper surface? Do the acquous inkjet both pigmented or dye ruin fuser, rollers, developers, drums, belt and so on once heated to the needed temperature in order for a laser printer to print? About 220 °C if I recall correctly maybe the ink could boil and burn under these temperatures. TL;DR: I don't want to ruin a copier or a production machine with some tests unless someone help me in the choice :D

3. Let's say that the safest way is to print first in the laser machine and then in the inkjet, the laser toner would be covered in ink. This could create problems if one want to post finish the part like with foil or something else that use toner in order to stick ?

Thanks for the replies

Best Regards

Answer 1

Could an Inkjet printer be ruined by the presence of toner on the paper surface? Can an inkjet printer overprint safely a laser print with also a thick toner density ?

Consider that a laser printer uses powdered plastic, which is essentially melted/bonded to the paper fibers. The locations at which the toner is applied will reject any ink from the inkjet printer. If the paper path is convoluted, there is a very small risk of flaking the toner off the paper, but it's extremely small. One can laser print a dark image and fold it/crease it will no deterioration from a single fold. The typical printer (either kind) does not have folding/creasing, hence the "very small" reference.

Could a Laser printer be ruined by the presence of inkjet ink on the paper surface? Do the acquous inkjet both pigmented or dye ruin fuser, rollers, developers, drums, belt and so on once heated to the needed temperature in order for a laser printer to print? About 220 °C if I recall correctly maybe the ink could boil and burn under these temperatures. TL;DR: I don't want to ruin a copier or a production machine with some tests unless someone help me in the choice :D

One would desire to ensure that the ink has dried before running it through a laser printer. Many inkjet inks are alcohol based, which has a reasonably fast drying time. Once the alcohol or other solvents/carriers are evaporated, boiling is unlikely. According to one reference, the majority of consumer inkjet printers use dye-based inks. The dye is absorbed into the paper, effectively removing any particulate concerns.

Note that dye-sublimation printers use a plastic film of multiple layers to create the desired colors for a particular image. This film is subject to the heat within a laser printer and should not be used in the manner described. No reference for this, as it is personal experience. The expression "gum up the works," comes to mind.

Let's say that the safest way is to print first in the laser machine and then in the inkjet, the laser toner would be covered in ink. This could create problems if one want to post finish the part like with foil or something else that use toner in order to stick ?

You'd want to create your work in such a manner as to avoid overprinting on the laser printed portion. As noted earlier, you'd be spraying liquid on a melted plastic surface. In the case of images, the dot pattern would have some white, non-printed areas, but the proportions would favor the non-white image content.

To accomplish the post-processing you suggest, it might be necessary to blot any remaining ink from the work before running the foil. Remaining pigment from the inkjet may also prevent the foil from bonding, but this is something that would require testing.