Another can of worms!
Modern monitors (additive RGB) are inclined to have a contrast ratio way higher than a print (subtractive CMYK and relying on reflected light). In other words, the monitor's white is much brighter than you would normally get by looking at at white piece of paper under normal (indoor) lighting. Turning down the monitor contrast (white point) is often necessary to produce comparable results.
That doesn't help you - sorry. I'd suggest using QImage for printing, and you can set batch defaults, but there is a learning curve.
Alternatively, rather than adjusting the images in PS, you should be able to alter the settings in your printer driver to increase the brightness. Look at Print > Properties and there will be a load of values you can adjust, depending on your printer.
That's just a quick fix, but it may get you there for now.