I don't usually print with watermarks or with an aspect ratio different then my pictures. Long story short I'm printing some 3:2 aspect ratio images at 4:3 with a watermark. Whats happening is wherever lightroom initially places the watermark on the image when I select it for printing the watermark locks to that place on the printed image. When I adjust the crop (hold ctrl+click and drag) in the print module lightroom shows it in the correct place on screen but when it's printed its placement is in the same place from when I initially selected the file for printing. I would really like to see this fixed but does anyone know of a workaround that's easier then resizing every image before printing? I have about 40 pictures to print short term and more in the future, re-cropping each one and then going back and changing them all back to original is going to get old quick. The first one came out fine and I ran about 10 more before I went back to check on the printer and figured out what was happening. I'm glad I caught it early but at least 5 of them are unusable/sellable and being larger prints (18"x24") it's pretty annoying. The blue print on the lower right is correct, one got cut off all togeather and the portrait layout ones got shifted up/down. I found (THIS), it was posted about 5 years ago and that's all the info I found with my fairly quick search. Any help is greatly apreciated.
It sounds like you are using Lightroom Classic as you have real watermarks. The trick to do what you want is to use the print panel. When you export from Lightroom Classic, it will NOT change the aspect ratio if you sepcify a size in the export panel. It will simply fit the slightly longer rectangle inside the rectangle you specify. This is why in your prints the watermark still gets cut off since the printer you are using is cropping for you at 4:3 which will cut off the part of the watermark in the corner of the 3:2 exported file. What you do is set up a 4:3 print in single image mode and select JPEG File in Print Job. Set the Custom File Dimensions to 18x24 and resolution to 300, print sharpening to medium and the media type to what you will print on and jpeg quality to anything above about 85. Use sRGB or whatever printer profile you got from your print shop. Then maximize the print area in the cell area area, select zoom to fill and rotate to fit and enable watermarking and choose your watermark. Hit print to file and you'll get a bunch of jpegs correctly sized with the watwermark in the correct spot and won't cut it off and you don't have to crop all your images as it is done automatically. If you need to crop differently than the automatic crop, you can change it moving the images around in the print interface.