Do you like Lightroom’s print layout capabilities, but don’t have a printer to print to, or want to just share your design electronically?
No problem — design your layout in the Print module, and print to a jpeg instead of to a printer. Send the jpeg out for someone else to print, or email it out to your clients or friends. In the Print Job panel in the bottom right, change Print to: Printer to Print to: JPEG File.
Set the file resolution to whatever your printing service requires (or 90-100 for onscreen display), sharpen if you know your printing service won’t. For the best print quality, set the jpeg quality to 100. For onscreen viewing, I find 70 to be sufficient — it produces a much smaller file that can be easily emailed, with no visible quality deterioration. Under color management, choose sRGB, unless your printing service gives you a profile to use.
Once you choose Print to: JPEG file, the Print… button at the bottom of the panel becomes Print to File…
Click on it, and tell Lightroom where to save your JPEG to.