HP Paper (Glossy) Q1421A is compatible in the following HP Models:

HP DesignJet T770 Printer series

HP DESIGNJET T770 24-IN PRINTER - CQ305A
HP DESIGNJET T770 24-IN PRINTER WITH HARD DISK - CQ306A
HP DESIGNJET T770 44-IN PRINTER - CH539A
HP DESIGNJET T770 44-IN PRINTER WITH HARD DISK - CN375A

HP DesignJet T620 Printer series

HP DESIGNJET T620 24-IN PRINTER - CK835A

HP DesignJet T610 Printer series

HP DESIGNJET T610 24-IN PRINTER - Q6711A
HP DESIGNJET T610 44-IN PRINTER - Q6712A

HP DesignJet T1200 Printer series

HP DESIGNJET T1200 44-IN POSTSCRIPT VERSION PRINTER - CK834A
HP DESIGNJET T1200 44-IN PRINTER - CH538A

HP DesignJet T1200 HD Multifunction Printer series

HP DESIGNJET T1200 HD MULTIFUNCTION PRINTER - CQ653A

HP DesignJet T1120 Printer series

HP DESIGNJET T1120 24-IN PRINTER - CK837A
HP DESIGNJET T1120 44-IN PRINTER - CK839A
HP DESIGNJET T1120PS 24-IN PRINTER - CK838A
HP DESIGNJET T1120PS 44-IN PRINTER - CK840A

HP DesignJet T1120 HD Multifunction Printer series

HP DESIGNJET T1120 HD MULTIFUNCTION PRINTER - CK841A

HP DesignJet T1100 Printer series

HP DESIGNJET T1100 24-IN PRINTER - Q6683A
HP DESIGNJET T1100 44-IN PRINTER - Q6687A
HP DESIGNJET T1100PS 24-IN PRINTER - Q6684A
HP DESIGNJET T1100PS 44-IN PRINTER - Q6688A

HP DesignJet T1100 MFP series

HP DESIGNJET T1100 MFP - Q6713A

HP DesignJet 800 Printer series

HP DESIGNJET 800 PRINTER (24 IN) - C7779B
HP DESIGNJET 800 PRINTER (42 IN) - C7780B
HP DESIGNJET 800 REMARKETED PRINTER (24 IN) - C7779BR
HP DESIGNJET 800 REMARKETED PRINTER (42 IN) - C7780BR
HP DESIGNJET 800PS PRINTER (24 IN) - C7779C
HP DESIGNJET 800PS PRINTER (42 IN) - C7780C
HP DESIGNJET 800PS REMARKETED PRINTER (42 IN) - C7780CR

HP DesignJet 5100 Printer series

HP DESIGNJET 5100 PRINTER - CG710A

HP DesignJet 510 Printer series

HP DESIGNJET 510 24-IN PRINTER - CH336A
HP DESIGNJET 510 42-IN PRINTER - CH337A
HP DESIGNJET 510PS 24-IN PRINTER - CJ996A
HP DESIGNJET 510PS 42-IN PRINTER - CJ997A

HP DesignJet 500 Printer series

HP DESIGNJET 500 24-IN ROLL PRINTER - C7769B
HP DESIGNJET 500 42-IN ROLL PRINTER - C7770B
HP DESIGNJET 500 42-IN ROLL REMARKETED PRINTER - C7769BR
HP DESIGNJET 500 PLUS 24-IN ROLL PRINTER - C7769F
HP DESIGNJET 500 PLUS 42-IN ROLL PRINTER - C7770F
HP DESIGNJET 500 REMARKETED PRINTER - C7770BR
HP DESIGNJET 500PS 24-IN ROLL PRINTER - C7769C
HP DESIGNJET 500PS 24-IN ROLL REMARKETED PRINTER - C7769CR
HP DESIGNJET 500PS 42-IN ROLL PRINTER - C7770C
HP DESIGNJET 500PS 42-IN ROLL REMARKETED PRINTER - C7770CR
HP DESIGNJET 500PS PLUS 24-IN PRINTER - C7769G
HP DESIGNJET 500PS PLUS 42-IN PRINTER - C7770G

HP DesignJet 500 Mono Printer series

HP DESIGNJET 500 MONO 24-IN ROLL PRINTER - C7769E
HP DESIGNJET 500 MONO 42-IN ROLL PRINTER - C7770E

HP DesignJet 4520 Printer series

HP DESIGNJET 4520 42-IN PRINTER - CM767A
HP DESIGNJET 4520PS 42-IN PRINTER - CM768A

HP DesignJet 4520 Multifunction Printer series

HP DESIGNJET 4520 HD MULTIFUNCTION PRINTER - CM769A

HP DesignJet 4020 Printer series

HP DESIGNJET 4020 42-IN PRINTER - CM765A
HP DESIGNJET 4020PS 42-IN PRINTER - CM766A