For an image to have drop-shadow, there must be a solid layer underneath it for the shadow to drop onto.
Start with a jpeg image sized for the paper you intend to print on. This image must be a regular layer so if it is a ‘Background’ layer, convert it by holding down the [Alt] key and double-clicking the word ‘Background’ on the layer in the Layers Panel. It should then become Layer 0.
Add a new layer and with this layer active, select the Paint Bucket tool, make sure the Foreground colour is white, and then click anywhere on the image to fill the layer. Drag the white layer to the bottom. (in fact, it doesn’t have to be white; any light colour will do)
Make the image layer active, press [CTRL] [T] (transform) and with the [Shift] key held down to maintain the shape, make the image layer smaller to give room for the drop-shadow. Centralise the image before accepting the transform (you can use the arrow keys for fine tuning.
With the image layer still active, apply the drop shadow as follows:
Right click on the blue section of the layer name to reveal the Layer Style panel.
Left click on ‘Blending Options’.
Left click on the word ‘Drop Shadow’ and set to taste. If you move the panel away from the image, you can see the effect.
Here’s some settings to try. Dark grey shadows look better than black (I think!)
