HP LaserJet 4345 Multifunction Printer series - Manual (Page 287)

Determining memory requirements
The amount of memory you need depends on the types of documents you print. Your MFP
can print most text and graphics at 1,200 dpi FastRes without additional memory.
You might want to add more memory to the MFP if you often print complex graphics or
PostScript (PS) documents, print two-sided documents (duplex printing), or use many
downloaded fonts.
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