Photoshop Tips & Tricks
Cutting glass and transparent objects in Photoshop may seem like a difficult task, but actually is easier than you think. There are many different techniques, but today I will show you a method that is non-destructive and let you adjust the effect by adjusting the shadows and highlights via the Levels adjustment layers. All you need is a background you like to use to place your object and an image of your glass object preferably over a light background.
Open the image you want to use as a background for your glass object in Photoshop.
Go to File > Place Embedded. Locate the glass object image (in this case, a bottle) on your computer and click the "Place" button.
Using your favorite method make a selection around your subject, which in this case is the glass bottle.
With the selection active go to Layer > Layer Mask > Reveal Selection.
Rename the layer to "Shadows" and set the blending mode to "Multiply".
Go to Layer > New Adjustment Layer > Levels. In the Level Properties panel be sure to check the "Clipping Mask" icon and adjust both the Shadow and Midtone Input Levels.
In the Layer Panel select the "Shadows" and the Levels adjustment layers and go to Layer > Duplicate Layers.
Rename the "Shadows copy" layer to "Highlights", set the blending mode to "Screen" and the Fill to about 95%.
Select the copied Levels adjustment layer and again adjust both the Shadow and Midtone Input Levels until only the highlights are visible.
Make a copy of the "Highlights" layer and go to Layer > Arrange > Bring to Front.
Rename the layer to "Cap", set the blending mode to "Normal" and bring back the Fill to 100%.
Lastly, select the Layer Mask thumbnail in the Layers Panel, and using a black brush color paint over the bottle part to hide it and only let the cap be visible.