Bitmapping and Color holding

– Go to Image > Mode > Greyscale. Click discard.
– Image > Mode > Bitmap
– Click the flyout and select halftone. Click ok.
– Lower the frequency. In class, I lowered it to 8 and 10. With a higher resolution image, it might be higher to get the halftones to be really apparent. Click ok.
– Once satisfied, Image > Mode > Greyscale. Click ok. Image > Mode > RGB
Color holding  (creating an image with a transparency using channels)
– Have a bitmapped image, black and white image or high contrast line work in the background layer.
– Create a new layer.
– Click on channels.
– Hover your mouse over the RGB preview icon. Hold Command and click on the icon.
– Go back to your layers panel. Select > Inverse or Command + Shift + I.
– Fill your background color in your color pallet with your designed color. Hold command, press delete. This should fill your selection or layer with your background color.
– Command + D to deselect.
Transparency lock
– In your layer locks, first on the left is lock transparency.
– Click on that. A lock symbol will appear.
– You can with fill it in or you can brush in whatever color without coloring outside the line or fill.
– Unlock it and use layer blending mode, layer masks or anything really as you see fit.