I print primarily black and White photos I just picked up an HP8150 and I am using the hp100 gray cartridges. after running through several cartridges on a long print job i got the idea to "refill" these using the black ink in all 3 ink wells and then adjusting density and brightnesssaturation in orderto achieve acceptable high contrast prints. I'm pleased with the results so far and have made some quite striking prints. As for the color cartridges I have used the inks on aHP PSC750 With acceptable results. I did have a problem with leakage in a black 45 cartridge but I suspect this to be my fault in not having achieved proper vacuum seal.As to the post about abpout voiding warrantiesetc. This is NOT true unless your printer comes with free ink you cannot void thewarranty of your printer byrefilling. However havingsaid that you can be expected to PAY for any repairs as a result of leaky ormisinstalled cartridges.