Very Slow in printing the generated invoice PDF

Very Slow in printing the generated invoice PDF

I understand that generating PDF can sometimes slow depends on the network and server condition.

But I witness my user spend a lot of time in waiting the generated PDF printout. It seems printing the PDF to printer is extremely slow.

My generated PDF size is just around 140kb (which is very small)! The only image I used is the Facebook "Like Us" icon.

Does anyone experience this and got any suggestion? 

A sample PDF is attached.

Simon.