You might make your stroke on a new blank layer so it's easier to fix those problems.

For example, Ctrl click on the layer in the layers panel that you want to put a stroke on (this makes a selection of the pixels on the layer)

Then make a new layer and Edit>Stroke.

You can then use the pencil tool or the eraser tool to fix the feather effect (for lack of a better word).

You can resize both the layers at the same time by selecting them both before transform.

The thing you see around the image that looks like a selection with handles is the Bounding Box (you see that when using the move tool)

cboerens,

When i have several layers which are generated in the course of enhacing the picture file, I create a stamp visible layer at the top of the stack of layers. This combines all the layers without flattening, and, retains the layer structure below. To do this, open a blank layer at the top of the stack, and press CTRL+SHIFT+ALT+E on the keyboard.

Now, to add a stroke, go to Select>all (or CTRL+A), open a blank layer above the stamp visible layer, go to Edit>stroke and position it inside.

If you want to change the color of the stroke, you can delete the layer with the stroke, and do it over. However, you can also open a color fill adjustment layer above the layer with the stroke, select your color, and clip the adjustment layer to the stroke layer (Layer>create clipping mask).

If you would like to learn how to create a nice frame, rather than a plain stroke, please advise ---something like this:

OK, there's nothing unusual about your layers.

I think that what you're seeing are the artifacts created by repeatedly resizing the image (and its stroked outline).  When I reduced the size of an image (without a stroked outline) that's in a larger canvas, I see a semi-transparent edge around the image of about 1 pixel in width (zoomed in to 2,000% to see it clearly).

Here's what I suggest for your workflow:

1. Do all the editing to the images you will be using on the image files themselves.
2. In your final document, use File...Place to bring each final image in on its own layer as a Smart Object.
3. Re-size and place the Smart Objects as required.  Using Smart Ojbects means that if you later resize the images, they will have less pixelization because the new size is obtained by using the original image and not the previously resized image.
4. Create a new blank layer above each image to hold the outline.
5. Ctrl+click on an image thumbnail in the Layers Palette to get a selection of all the non-transparent pixels.
6. Activate the appropriate blank layer and use Edit...Stroke to apply the outline.

After the fact, if you decide to change the sizes of the images, delete the layers holding the outlines and proceed from step #3.

Added:

Keeping the outlines on their own layers makes it ridiculously easy to change the colour and style of the outlines by clipping a Hue/Saturation adjustment layer to the outline's layer, or applying a layer style to that outline's layer, etc.

Ken

Message was edited by: photodrawken to add comment.

Hi Christoph,

cboerens wrote:

 

I am a bit afraid that I may acidentially resize only the image, not the border layer

That's OK.  The point is to have the the image and its border as separate layers so you never need to resize the border -- if you resize the image, delete the old border layer (or delete the contents of the border layer) and do the border again.

Ken