In this Inkscape Help Article, I’ll show you how to easily create center guides in Inkscape to help you easily align objects to the center of your composition. This is a feature I use a lot in other programs like GIMP to help speed up my workflow, though GIMP, in particular, comes standard with a feature that allows you to create center guides via a menu (View>Guides>New Guides by Percent).
Inkscape, on the other hand, requires a bit of a workaround, although it is still very easy to accomplish and produce the exact result we need. Let’s begin!
1. Get the Size of Your Document
The first thing you need to know for this technique is the vertical and horizontal size of your document (including the unit your document is in). To find this information, go to File>Document Properties.
This will bring up your Document Properties dialogue box. Here, you will see a section titled “Custom Size” (outlined in green in the photo above), with the height and width of your document displayed on the left, and the document units displayed on the right. In my case, I set my canvas up to be 1920 px x 1080 px (I also performed a few steps that I discuss in this tutorial on How to Make Your Inkscape Canvas Look Like Illustrator’s Artboard, which is why I have a dark gray background and white canvas), and so these are the dimensions displayed for my document. The unit is also set to px (pixels – denoted by the red arrow in the photo above).
I’ll keep this information in mind for the next step in the tutorial, and will close out the Document Properties dialogue box by clicking the “X” in the top right corner.
2. Draw a Rectangle
Now that I know my document size, I’ll grab the Rectangle tool (denoted by the red arrow) and will click and drag from the top left corner of my document (blue arrow). Make sure your “Snap to page border” option is enabled (green arrow) so that your mouse will snap to the corner of the document as you draw. This ensures your shape is actually aligned to the edge of the document. It doesn’t matter how large the rectangle is right now – just make sure it is drawn from the very top left corner of the image.
After you have drawn your rectangle, you will see the width and height of the rectangle displayed in the Tool Controls Bar (outlined in green in the photo above). In my case, my rectangle came out at a width (W) of 1000.36 pixels and a height (H) of 584.187 pixels.
I will change these values to equal one half of the total document width (remember, this value was 1920 pixels – so one half of that would be 960 pixels) and one half of the total document height (the original document height was 1080, so one half of that is 540 pixels).
The Rx and Ry values next to the width and height represent how rounded the corners of your rectangle are. You can keep both the Rx and Ry to 0 for now as we do not want or need rounded corners on our rectangle.
3. Set Guides to Your Rectangle
After you have drawn your rectangle, and set it to half of the width and half of the height of your overall document (960 x 540 pixels in my case), go to Object>Objects to Guides.
This will cause your rectangle to disappear, and guides to appear in its place. There will be 4 guides total – two of them along the corner of your document (one vertical guide – labeled 1 in the photo – and one horizontal guide – labeled 2), and two of them along the bottom right corner of the now-disappeared rectangle – which happens to be the exact center of your document (labeled 3 and 4).
We do not need the first two guides in the top corner of the image, so we can grab the Selection tool (red arrow in the photo above), click on these guides one at a time (the guide will turn red when you are hovered over it – as you can see in the photo with the guide that was previously labeled 1), and press the backspace key on the keyboard to delete them.
Now, you will be left with center guides on your composition!