Here are some screenshots demonstrating what happened. This is the file before flattening: After flattening: And without "dissolve" on Layer 21: ... View more

Christian Davideck, thank you. That was simply the solution! Because my file was a very high resolution, the preview of the layer blending in the unflattened image looked radically different to the rendered version of the blending when flattened. Hence, when I lowered the resolution, the unflattened preview and the flattened final looked almost identical. Similarly, in the original file, if I zoomed in, the unflattened and flattened versions looked identical. I take back all the bad things I said about Photoshop. Sure inaccuracy of previews while editing are annoying, especially the change in appearance at different zoom levels, but the flaw is nowhere near as heinous as I imagined. I am not sure if this is a solution to StrongBeaver's original problem, but it might help... ... View more

StrongBeaver. All I can say is that at least I UNDERSTAND your problem. I have just encountered it myself. You are one of the few people who has actually worded it properly, and STILL you received patronising and completely misunderstanding replies. I am using Photoshop Elements 4.0 on a mac and when I merge layers with blending, the visual effect of the blending is lost. This is completely ridiculous: Layer blendings have no purpose if you cannot flatten the image while keeping the VISUAL EFFECT of a blending mode (NOT the blending mode itself, as some people have misinterpreted). You need to flatten an image to do almost anything with a photoshop document. In older versions of photoshop, this was not an issue - flattening an image reproduced EXACTLY what appeared on screen. If there is no solution to this very real problem, then Layer Blending is COMPLETELY useless, and only for show. This is a very serious problem with the program and I am surprised that it hasn't been brought up more often. I apologise if someone did post a solution that works. ... View more