You can get computer and printer support from wonderhowto.com and find step by step instructions that will teach you how to refill up an old, used ink cartridge and print with invisible ink. Invisible ink is ink that can only be seen on paper by using a UV light. There is an easy way that you can transform your old, used up color ink cartridge into a refilled cartridge loaded with invisible ink.
There are a number of reasons why you may want to use invisible ink for printing jobs, besides the fact that it is really cool, you can print documents that you would like to keep private and store them until you need to reference them. Only you will know what they contain when you look at them using a UV light. It is also a neat trick to show others a fun activity for your children to do.
All that you need to complete this job is an empty ink cartridge and four pens that contain invisible ink. Once you remove the empty ink cartridge you can clean out the sponge inside of it, this is where the ink will be stored. Empty out the ink from the four invisible pens into a clean receptacle and use a syringe to suck up the ink and inject it into the sponge. Place the cap of the cartridge back on and reinstall your printing cartridge. This process should only take a few minutes of your time.
Now you are ready to print out your documents in invisible ink. Just make sure that you switch the color that you are going to print in on your computer to yellow so that your document or picture only prints in the invisible ink color. Fell free to get creative or secretive! It is entirely up to you.