Although I’ve already covered a nice method of bordering an image (which can probably use improving), I don’t actually use that method. While it gives a lot of flexability and freedom, it takes a bit of work to set up. Instead, I use a simple method that’s pretty quick to do, but doesn’t give so many options if I want to change it around later.
Open Inkscape and insert an image to be given a border. You’ll want a few things ready in Inkscape, as well. For starters, if rulers are hidden, you can use “View, ShowHide, Rulers” to make them visible, or just press Ctrl+R. Also, ensure guides will be visible via “View, Guides” (or by pressing the | pipe key). “View, Snap” (or %) will ensure that drawing the border later will cause it to “snap”, to line up with the guides you’ll draw.
Click on the top ruler and drag down to pull a horizontal guide line down. Start from the left instead to get a vertical line. If you’re near the top-left, you’ll get a diagonal line, but that won’t be used in this tutorial.
Drag two horizontal guide lines and two vertical guide lines over your image. Place them were you want the borders to be.
Select the squares/rectangles tool from the left toolbar (F4). Click on the top-left intersection of the four guide lines to start drawing the rectangle, then drag the mouse to the bottom-right intersection. There’s no need to precisely draw out the shape. If the mouse click at the start and letting go at the end of dragging out the shape are close enough to the intersections, they’ll snap onto them.
At this time, you can change the width of the stroke as desired (Ctrl+Shift+F, under the “Stroke Style” tab).
Duplicate the rectangle (Ctrl+D). At this point, only the duplicated rectangle is selected. The goal is to select the image as well, so the image and the duplicated rectangle are both selected. Do this by Shift+Click’ing on the image.
Clip the image with the duplicated rectangle. This is “Object”, “Clip”, “Set”. I currently use “Alt+O, p, s”, but will probably set up a shortcut key for this action once I get more comfortable with methods of doing things in Inkscape.
What’s this? The original rectangle is still over the now-clipped image! Since the clipped image is still selected, raise it up higher (“Object, Raise”, or simply press the PgUp key).
And that’s all there is to it! You can either keep the lines or remove them. When working on a comic with a number of panels, I like to move the lines over to use for the next panel, but some may prefer to have lines for every panel cluttering the page all at the same time.
That should suffice for this tutorial.