Panasonic KX-P8420 Manual

To find the best image resolution for your purposes, make test prints of 
some raster artwork at different resolutions. Start with a high-resolution 
image (400 ppi) and save versions at progressively lower resolutions, down 
to 100 ppi, using a pixel-editing application such as Photoshop. Always 
save a copy of the original high-resolution version in case you need to 
revert to it. The high-resolution data cannot be recreated from a lower 
resolution version. 

Print the files and examine the output. You will likely begin to see a marked 
deterioration in output quality at resolutions below 200 ppi, while above 200 
ppi the improvement may be very subtle. 

Raster images prepared for offset printing may need to be at higher 
resolutions than needed for proofing on your KX-P8420. 

Ideally, each raster image should be saved at the 

actual size it will be 

placed into the document and at the 

optimal resolution for the print device. If 

the image resolution is correct for the print device, there is no quality 
advantage to be gained by scaling an image down to a percentage of its 
actual size. If you scale a large image down to a percentage of its actual 
size, you incur unnecessary file transfer time because the image data for 
the entire large image is sent to the printer. If an image is placed multiple 
times at a markedly different sizes in a document, save a separate version 
of the image at the correct size for each placement.

If you need to place an image at greater than 100% in a document, 
remember that the output image resolution is affected. For example, if you 
scale a 200 ppi image to 200%, the image is printed at 100 ppi.

100 ppi

200 ppi

300 ppi

400 ppi

Image quality

Image resolution