Painting transparency? Adjusting the size of a painting tool to pixels?
I'm new to tools like Photoshop. The title says it all -- that's what I'd like to know how to do.
I have some old sprites that I'm using for a project, and the sprites are bitmaps (bmp format), 16x16 pixels, with two colors -- white for the symbol, and black for everything else.
What I'd like to achieve is making the black pixels transparent.
I also encountered an oddity (as a newbie) -- the paint tools' radius is too large for editing individual pixels when zoomed in at 3200%. What is the best method to adjust the radius to 1 pixel?
Also, these image files are intended to be sprites for a simple game project. Is bmp the best file format? Are there others, such as png or jpg recommended?
Use the pencil tool instead of the brush tool, and right-mouse click on the canvas to set the size to 1px if required.
Png is nowadays the best format for this type of graphic, but the bitdepth depends on the what the developer requires. 32bit png (24bit+8bit transparency) is always safest. In your case 8bit png with 1bit transparency is fine.
To convert those black pixels to transparent ones in the png file, add a layer mask, and paint with black to mask out those pixels. Then save for web, png 8bit, and those black pixels will be hidden.
Btw, if you intend to create a lot of pixel art, working with such small graphics (16x16) you may want to switch to an art program dedicated to pixel graphics, such as graphicsgale. They make the creation of pixelart arguably easier and more comfortable. Well, it depends.
One issue with the current versions of Photoshop (CS6 and CC) is that they only zoom in to 3200% - which may be insufficient when you are working on a higher resolution larger screen. I work on 27" @2560x1440, and the 3200% is not quite enough. You need at least 6400% zoom to work comfortably with pixeling at times (at least, I do).