Today’s Question: When I return a photo back from Photoshop to Lightroom, I first flatten the image, then Save and Close. Am I wrong to flatten the image?
Tim’s Quick Answer: In my opinion, with very few exceptions, you should never flatten your original “master” image in Photoshop. Instead, I feel the layers should be preserved so you can always make changes to any of the layers at a later time.
More Detail: There are certainly scenarios where an image needs to be in a “flattened” state, without any layers. For example, if you are sending an image to a client you probably don’t want them to be able to see or modify any of the layers in your source image, so you would send them a flattened version of the image.
However, for the “master” image you are using as the basis of any output you produce for a photo (such as printing or sharing online), I recommend keeping the layers intact. In other words, you should not flatten the master image.
To be sure, an image with layers will have a larger file size than a flattened image. However, by keeping the layers intact you are retaining the ability to open the image in Photoshop once again, and make modifications to any of the layers. For example, you might find that some of your image cleanup work resulted in some visual artifacts that you need to correct. Or you might change your mind about one or more of the adjustments you’ve applied to the image. Keeping the layers intact provides you with that flexibility.
So, while you might flatten a copy of an image (or simply use the Save As command to save a new copy of the image without layers), I always recommend retaining the layers in the “master” version of your image. I’m more than happy to have a larger file size in return for the greater workflow flexibility that layers provide.