KB Article: http://support.microsoft.com/kb/2596574
Consider the following scenario:
- You copy a region of a workbook in Excel 2010. The region contains a .png, .jpg, or .gif picture.
- You paste the region as a picture in another workbook in Excel 2010.
- You print the workbook that contains the pasted region.
In this scenario, the pasted region is printed in low quality.