I print from PS to an Epson P6000. Typically my images are from film cameras, and the images are 'floated' into a standard paper size. I.E. my customers might shoot a square image, and order an "8x10" print with their image floated in the page, with lets say a 1" border. What I'll do is exactly what I do in the darkroom, place the image with a weighted bottom.
What I'm trying to do is arrange a number of 8x10s in this fashion when printing with roll paper. Unfortunately the cut guides in PS are insufficiently exact when cutting in my opinion. Ideally, I'd have a full faint line sitting 1mm or so outside of the border of the paper edge. LR lets me do this, but I find that the LR printing program is completely broken at the moment. It fully refuses to work with my P6000...long story.
Is there an easy way to do what I'm trying to do? BTW the reason I print this way is because it simplifies the ordering process, and people can use standard frame sizes.