A new version of the flush image is below.
Use this image to flush ink from your print head and/or to verify that you have removed traces of the previous ink set from your printer. Use it as described in the ink change procedure for your printer (available here). Please realize that large format printers require other steps in addition to printing a flush image when changing inks.
To use the flush image, print it from an imaging program (such as Photoshop). Leave it as a color image, and print it through the Epson driver on copier paper. When used in this way, you will push ink through all the nozzles in your print head.
Comments about the R800, R1800, 4000 and 4800 printers: These printers have both a matte and photo black cartridge in them. To ensure that you print the image through both black channels on all three printers, plus the Gloss Optimizer (GO) channel on the R800 and R1800 printers, print the image once using a matte paper setting, and once using a gloss paper setting. The choice of media setting on all three printers determine which black ink, and whether the Gloss Optimizer is used.