Sometimes you may want to add a watermark or copyright message to your photos to have some form of protection against unwanted reuse by others. This article describes how to make one in GIMP and how to place it on a photo – so the manual way.
In another article I’ll show you how to do this using some plug-ins for GIMP or using Digikam and in yet another article how to add a watermark to a series of photos using ImageMagick or gmic.
Your watermark may be a text or a logo or both and it may be visible or invisible. An invisible watermark can serve to prove the ownership of a photo in a copyright dispute, by making the invisible watermark visible again before the eyes of a judge. But most likely you want a visible watermark. Adding your name or a logo to a photo means essentially that you add a new layer to the photo. This layer contains the text or the image that you ‘overlay’ upon the photo. The size of it must fit the size of the photo, that’s why it’s a good idea to think in percentages. Because it is a layer, you can adjust the opacity and make it less or more visible and place it wherever you want.
Here we are going to make a watermark for a small 600 x 600 pixels photo. Open GIMP and make a new file by clicking in the menu on File, then New. In the window that appears, choose an appropriate image size (say 200 x 100 pixels) and say under Advanced options that the new image must be transparent.
Click OK and you’ll see this.
Activate the text tool in GIMP’s toolbox by clicking the A.
Click on the image area and the text tool appears. Choose your font, size and properties. About the size: all depends on the number of pixels of the photo that you want to watermark. In general, a font size of 10% of the long side of the photo is too big, 5% is better, 3% more discrete. Now type the text you want to appear on your photo, I use ©ppp2016 here with font size 30 (this equals 5% in this case). When you’re done, save this file as my.watermark.png for example. The png format is important here, as it saves the transparency as well, a jpg would be filled up with the actual background color of GIMP.
Adding the watermark
Open the photo you want to watermark. We are going to add the watermark as a new layer. Click in the menu on File, then Open as layers… Navigate to the file my.watermark.png and click OK. That looks so.
(Photo taken outside Rotterdam Central Station, the Netherlands, and processed with G’MIC’s CMYK color mixer).
The Layer window (Ctrl+L) shows indeed a second layer on top of the photo.
When this layer is active (indicated by the blue background in the screenshot above), we can reduce the opacity of the text layer, at 0 it is invisible, at 100 it’s max. We can move it to another position by hitting the M key. In the Tool options window you can pick which layer to move, or say Move active layer.
After re-activating the image window by clicking somewhere in it, move the text layer with the arrow keys (pixel by pixel) or with Shift+arrows for bigger steps. Or use the mouse if you want.
Black and white
Moving this text to a dark underground makes it harder to read. One solution for this – especially useful when you want to add a watermark in batch to a series of photos – is to add a white contour to the text, like so.
Go to the Layer window and hit Ctrl+Shift+D to duplicate the active layer. The window looks so.
Be sure the copied layer is active, then click in the GIMP menu Colors – Invert. The text changes to white. To see both colors, we need to move the white text a few pixels. Hit again the M key and move the layer with the arrow keys. That looks like so.
Make the black dominant again by sending the copied layer one level down (use the Down arrow key in the Layer window for that, indicated in red here).
To link both layers so you can move them together, click in the white (empty) field next to the eye symbol and a chain symbol appears.
As you can see, the text stays visible on a dark and on a light background.
Some people add some blur to one of the layers, to make it a bit more difficult to erase the watermark. To do that, activate the layer and choose in the menu Filters, Blur, Focus Blur for example. You can use other tools as well on this layer, like scale, rotate or perspective, to be found in the menu under Tools, then Transform tools.
You might want to add this extra layer at the point where we created the my.watermark.png file, above.
Perhaps you think this is quite complicated, but I can tell you it is not! Once you get the feel of it, you can create and place any kind of watermark in just a few seconds. And once you saved your watermark, it is even faster!