From Designers File to Web Build File: Solving Special Transparency Problems with Essential Layer and Layer Mask Tricks
The methods I used in the actual project and in this exercise allow me to maintain what I call an "open-ended" image-editing environment. Whenever I am working in a production workflow, I try to use layers and layer masks as much as possible so that no image information is ever thrown away. I've seen changes come down the pipeline in the middle of a build process, and as long as I structure my file so that I've burned no bridges, it's always relatively easy to go back and make modifications to the build file and export additional image slices.
I also try to structure my file so that it's clear if anyone else has to work with what I've created. When I first made the empty layer that would be the destination for the merged layer, I named it 4-transp-gif so that anyone else who had to work with the file could see that this was the layer to use if a GIF needed to be exported. I also then went through my layers palette and grouped each image section into its own layer set and turned off the eye icons for the layers that did not need to be visible anymore. The only layers that were visible were the final merged composites. The other layers were still around, however, just in case changes had to be made and I needed to return to those original layers. Finally, I made sure that every layer and layer set had a clear, descriptive name.
This project is a good reminder that even if you're using Photoshop only to prep images for the Web, it helps to be familiar with some of the other essential skills and procedures that are used in more traditional image compositing. You never know when a designer will hand you a complicated file that's going to require some fancy Photoshop moves.