Sorry about the above mistake.
Hi Tamaris, the .Doc file I mentioned is simply a text file which you type into the printer using MS. Word or whatever you write your letters and documents with and, by printing it out, using coloured text (capital letters) of each colour (B, Y, R & BLUE) you will be able to see from the coloured text which colour has pale or white streaks running through it.
The instruction book which you got with the printer should tell you about the cartridges and how to take them out of the printer.
Once they are out of the printer (I assume you will have one Black cartridge and one Colour cartridge) stand the faulty cartridge in the saucer of hot water as mentioned above with the inky nozzle bit in the water.
You should now be able to follow the rest of the instructions in my first reply in order to clean the cartridge and get it printing properly again.
The bit about the ink absorbing carpet in the base of the printer was added as a point of interest about Canon printers and can be ignored for now.