Layer Mask on Smart Object

[善洋]

Hi all, I am new to Photoshop and I am not sure itsmy problem with smart object "normal"

My preferences Always Create Smart Objects when Placing is ON, by default.

My scenario: 

1. Place a .png image, it become a smart object.

2. Go Edit Contents. Select Subject. Add a Layer Mask. Successfully. (So the background gone)

3. Save and Close the smart object. looks OK.

Problem:

When I go to edit that smart object again, the Layer Mask is gone. Its likes "Apply and Delete the Layer Mask". So I can't do any "un-mask" to show the origin background back.

Is there anything I did wrong or this is the normal behaviour of smart objects?

For now I use below Workaround to keep my layer mask on smart object. (Not sure is any "side effect" )

1. Turn off  "Always Create Smart Objects when Placing", place png image and convert to smart objects.
OR
2. Convert the smart object to Layer, then convert to smart objects again.

Thanks for help in advance.

[c.pfaffenbichler · Accepted solution]

You could also stop using png for this and instead use a file format that supports Layers like psd. 

[Chris 486 · Accepted solution]

Hi Benji!

What you are experiencing is normal behavior for png files. They do not support the changes you are making to them in file so they file becomes flattened and all changes get built into the file when you close. You will need to support a file system that supports photoshop nondestructive editing. As c.pfaffenbichler recommend, .psd files are native to photoshop and will be perfect for you application. I would resave your png file as psd and continue your work from there if you want to keep it as a smart object. Or you can import the png as a layer into your file and work on it there.

[善洋]

Thanks Chris 486 & c.pfaffenbichler. 

I did not know that the file type is matter when using Smart Objects.
I think I will turn off the Always Create Smart Ojbects preference so any image will alwasys import as a layer.

Thanks again.