I have been processing and preparing image files to upload to Costco for my wife, and ran into a problem. Here is my workflow in Photoshop CC 2018 and Lightroom Classic:
1) I optimize the raw file in LR, then edit it in PS, and save it as a Tiff.
2) After opening the edited tiff again in LR, I softproof it using the downloaded Costco profile for the Fuji Frontier with Luster paper, making the softproofed version a Proof Copy, adjusted to look as close to the original Tiff as possible.
3) I send the Proof Copy back to Photoshop, where I make the canvas about 2% bigger so that when Costco makes the image a bit larger for full bleed I don't lose any of the actual image I want. I then switch from 16-bit to 8-bit, and Convert to Profile from Prophoto to the Costco profile.
While I did this with two files last week, and they were printed by Costco and came out fine after specifying "No Automatic Corrections," or whatever the actual term is, I repeated what I thought was the same procedure this week, with horrible results, looking way oversaturated and as if I somehow had double profiled them.
The question is, if I softproof an image in LR using the Costco profile, and adjust it to best resemble the original, and then convert the image to the Costco profile, is this actually causing a problem such as double profiling?