Canon S900 - Manual (Page 134)

Print Quality is Poor or Contains Errors 134
Troubleshooting
Windows
1
Open the Printer Properties dialog box.
2
Click the Main tab, select Custom for the Print Quality setting, then click
Set.
3
Click Diffusion for the Halftoning setting.
Macintosh
1
Open the Print dialog box.
2
For Print Mode, click Manual, then click Details.
3
Click the Quality icon, then click Diffusion for the Halftoning setting.