Exporting and Importing Layers or Masks
You can choose to either export layers or masks normally or export them in a flattened state. If you export layers or masks normally, Mari exports the selected layer or mask to an external location, as one of the supported file formats.
If you export layers or masks flattened, Mari flattens the selected item(s) into a single layer or mask and exports this to an external location. This does not affect the layers or masks in your current project, only the exported file.
Importing files into Mari to use in the Layers palette lets you import the file(s) into an existing layer. This takes the saved texture and imports it over any textures in the existing layer, thus overwriting the pre-existing textures. Alternatively, you can import the file(s) into the layer stack as a new layer. This automatically adds the new layer to the top of the stack, but you can move it to anywhere in the stack that you want.