Reader Robert G asks:

How does one prepare ones files in Lightroom to get them ready for Printing at a lab? I know a lot of people are doing photo books, calendars for Christmas gifts and it would be helpful. I still can not wrap my head around the whole sRGB, Adobe RGB, Pro Photo  colour space thing….

Good question.

First, though, the size. Typically for printing, the more pixels the better. But you can ask your printer – if you know the printer’s DPI and the size of the image, just multiply those. (a 10 inch long image printed at 300 dpi would need 300 x 10 = 3000 pixels).

Then the quality – assuming I am making a JPG, for print output I always set this to the highest quality (the lowest compression).

Now, the colour space for printing.

If you print from Lightroom yourself, it’s simple: no choice is needed since Lightroom and your PC use your printer drivers and profiles. But if you send out your image, the answer is simple if not helpful: it depends.

It depends on the printer used by the company that does your printing. Mostly, sRBG is what the print company expects. In some cases, it needs to be AdobeRGB – but usually you would be told if that were the case.

So produce a large high quality JPG in the sRGB colour space, unless your print company is able to handle one of the other colour spaces.

Which company, Robert also asked. I have recently used Vistaprint, and have been (and almost a year and a half later, remain) very impressed with quality, price, and speed.