How to preserve layers in Lr and Ps

I have been learning how to be proficient in using layers in Ps. I start in Lr then proceed to edit in Ps. I then Save as in Ps. Problem! When I go back to open the saved, layered image, the layers are no longer visible. I as if its been flattened. What did I do wrong? Thanks.

Layers are only saved in certain formats, including PSD or TIF,but not in JPEG. Secondly, there is a check box in the Photoshop save dialog box whether to keep layers or not. If you reserve then (export) them from Lightroom, the layers are probably flattened in the copy. The layers will be there if you open (edit) the original in Photoshop, but not as a copy, with or without Lightroom changes.

Thanks Ed. I have been saving the layered images in PS Raw.

Also in PS (I don't use Lightroom) there is an option in one pull down box to adjust the image or in a second pull down box, to add adjustment layer. The first option (I think) is a permanent change once you save it. The "add adjustment layer" saves the layers, so is reversible by deleting the layers.

Thanks Ed. I have been saving the layered images in PS Raw.

Raw doesn't support layers going back into LR.

You must save the layers in PS and it must be in Tif or PSD file. However, when you do, you will not see layers in LR, as that program doesn't utilize layers. But when you save your layers from PS back to LR they are still there, but you have to re-open in PS to use them. The process I'm talking about here is when you start in LR, choose to edit in PS and then save back to LR.

Lightroom does not recognize layers per se, but does see the composite results. If you use adjustment layers in photoshop, Lightroom will print the results as though the layers are intact. Any adjustments you do to a layered TIFF or PSD in Lightroom are applied when viewing or printing, but actually saved in an auxiliary file. IF you export a layered image from Lightroom, layers will not be reproduced and any changes in Photoshop or Lightroom will be made permanent.

LR will only see this composite image IF the user properly sets up preferences to write it: