Refilled the ink cartridges and now when we ask it to print, it goes through all the steps, but nothing on the paper. Printer is Canon I850.

If you had been printing right up until you refilled the cartridges then you have a problem. If you hadn't been printing for a while then you have a less annoying problem.

If you haven't printed for a while you probably have dried ink in the print head. So you need to start running it through cleaning cycles. If you see any printing starting to show up then there is a good chance it will eventually print normally. This can take 20-30 clean cycles and more.

If you had been printing until you refilled then the problem can be more serious. Some aftermarket inks are not compatible with Canon's inks and when they contact they form a sludge that is too thick to get through the print head. Again start running those print cycles and hope it starts to print.

If it will not print after running the cleaning cycles your other option is the try cleaning the head with a paper towel soaked in white (household ) vinegar. The Vinegar dissolves the inks dried or other wise. First remove the ink cartridges. Dampen the towel with the vinegar. You just need it moist not dripping. You want to gently pull the towel over the print head. You should see ink smears as soon as you touch the towel to the head. You need to be careful as the print head is delicate and you want to use lint free paper towels. The canon I had I could actually lay the paper down and move the print head by hand over it. After you get the ink off, go back and run a few cleaning cycles. It should start to print fairly quickly. If you manage to get enough ink off of the print head this can make your printer print like new as well.

Your only other option is trying a print cartridge will a bit of vinegar in that and running cleaning cycles. This will really clean the printer out but you will need to flush the vinegar out of the system after by doing cleaning cycles.

Unfortunately that is about as drastic as you want to get with a ink jet, Past that point you are better off looking at a new printer.

As much as I hate to say it, you might just try a purchased cartridge to see if there is a problem with the refills. If it doesn't print, then you can keep it as a spare and we can try something else.

If it does print, then might double check the refilled cartridges.