I want to style a layer with layer styles in Photoshop.
The problem is that I want to add multiple inner drop shadows.
I saw that you can do Right Click > Rasterise Layer Style, but then I can't change it anymore. Best would be if I could link a separate layer with it and apply the style to this one.
Can anyone help me out here?
Photoshop CS6 can have layer styles applied to groups. Groups can be nested. This is probably the best way to do it, because it's neat and everything scales nicely when you scale the document (for Retina etc).
Once you've applied some layer styles to a shape, you can convert it to a Smart Object and then apply more layer styles. You can still edit the layer styles inside the Smart Object by double clicking it.
Not ideal, because Smart Objects generated in Photoshop bitmap scale, so this technique isn't good if you intend to make Retina versions of images. It's also quite difficult to edit, because you have to open the Smart Object to make changes.
Works in Photoshop CS5 though.
You can also use shape layers and a clipping mask to do pretty much anything layer styles can do. Need a blurry inner shadow? Use Mask Feathering to blur your shape layers. Easy!
The only drawback is if you need to clip the result to another vector layer.
There's other ways to do this that don't require rasterising... let me know if the methods above don't suit.
To do this, I would duplicate the layer, bring it to the top, and set its
Fill to 0%:
This will set the Fill to be transparent but the layer effects will remain. Then you can change the settings of the top layer effect so that you can have two Inner Shadows. Here's an example with the shadows set to red and blue to show the result: