Not printing black dark enough, faded

Very strange error. I wonder if it is a driver issue? There were Microsoft Updates pushed out last night. Contact HP Support direct.

https://support.hp.com/ca-en/document/bpp03052

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I would suggest using the printers self head cleaning as it sounds like the heads need cleaning

check your printer settings, make sure color only is not checked off, or if you mainly print black and white documents, you should have that option checked, you may have to go into advance printer options to do this.

Many thanks for the suggestions received. Have been told by HP to
change the black printhead - which has solved the problem!

My printer does the same thing. I changed the blank ink yesterday (the printer shows the black ink was low) however after trying and trying and not being able to complete the alignment I decided to change the color ink as well.
It worked. Printer works fine now. Sometimes the ink dries up and you have to change it even though you know it should last longer.
Give it a try and let me know.
[email protected]

it is problem your printer black cartridge
you change it or
technicaly you drop your black cartridge in water withen two days after tow days you dry black cartridge and clean head printer maintai nence software then solve your problem

your cartridge is third party toner insert new hp original cartridge before cleaning

Hi,
Check whether the black cartridge is dry and whether it is releasing the ink properly.  This you can check by rubbing the paper on the place where the flows.
Else check with a new cartridge.  Even if the problem continues in the printer preferrence you have an option of service.  click on it and the problem will be fixed......!

It si not possible because the %darkness of the black ink and the black toner. The first is near 93% black and the toner even at ***** eye looks dark gray less than 90% black.

Are you sure this is a Designjet 450 (large format printer) and not a Deskjet 450 (portable printer)? The following assumes you have wispy black streaking on the printed side of the paper. If the streaking is on the back side then post more details of the printer model and the issue.

In either case the most likely cause is a buildup of fibers on the underside of the printheads or carriage, causing wisps of black ink to be dragged on the paper when the carriage reverses direction. You can clean the printer as shown at the following (though the details will be somewhat different for the Designjet or Deskjet....).

Regards,
Bob Headrick, MS MVP Printing/Imaging