I am not a front-end guy and surely not a web designer, but I promised myself not to avoid amateurial graphical work on occasion. While doing photomontages and altering images such as photos and movie posters, I learned some basic techniques and I now take great advantage of the editor's tools. I want to share these insights with the average programmer, who like me has seldom used a graphics editor and is scared by design work.

Selection is underrated in the minds of us programmers. Rectangular, circular, magic wand selections and similar tools are very sophisticate and composable: addition, subtraction and inversion of selections are the norm in a graphic's workflow. Selecting the right part of an image is fundamental for rendering the effects you want to apply, such as brush strokes, gaussian blur or even a bucket fill, to the correct zone instead of spreading them all over the image.

Working at an high zoom level - from 200% to 300% - gives you the opportunity for fine surgery. I guess this is why graphic designers have giant monitors, besides for fitting all the toolbars from Photoshop or GIMP on a single virtual desktop. Even when having an enlarged main view, you can always open another small view at a realistic scale to always have a glance at the overall picture.

Layers are the bread and butter of image editing, and every decent editor lets you modify, show and merge them independently, and combining layers of different sizes and positions in a unique image. If you are a web developer, I'm sure you have worked with CSS and the box model, so the concept of layering won't be a novelty. I store graphical works in the XCF format, which is the GIMP native format akin of the widely known PSD: both allow layers to be kept separately instead of being rasterized together in a JPEG or PNG. The separation of XCF from JPEG or PNG can be think of as the equivalent of source code and binaries: when you start playing with the source code you are transforming from an user to a programmer.

Transparency, often in the form of an alpha channel, is the glue that allows the composition of rectangular layers. Technically speaking, the alpha channel occupies 8 of the 32 bit of the color space, so that every pixel can specify its red, green and blue content with a total of 24 bits, but also its transparency (or by converse its opacity) to the point of being completely invisible.

Finally, another tool I find very useful in my pixel-obsessed, mathematical weltanschauung of image editing is the guide and the automatic snap of selections and layers to them or to the image borders. I simply cannot produce a decent work without setting up guides to attach layers to. I have not a perfectly steady hand while moving a mouse, which is not a precision device, but the combination of zoom and snaps lets me work like I was playing with Lego bricks or with my good old classes and objects.