Digitally signing a PDF document is not particularly that difficult, especially considering that most office suites usually provide this type of feature.

However what if you want to create a digital "classic" signature, like the ones you create by using a signature capture pad (like the ones you use at banks and other public establishments)?

Even though it's not the only way, or the best way (to be honest), you could try FingerPaint, a Linux-only application that allows you to basically draw using your laptop's touchpad.

At its core, FingerPaint is not what one might call impressive. Nevertheless, simplicity (more often than not) is better suited than complexity, and I have to admit that I found the app very satisfying to use (might also be because my laptop's touchpad is so smooth to the touch).

It's quite obvious that the app is mainly designed to help users digitize their signature (for basic document signing). Other use cases might include creating or writing complex characters (or symbols), as well as basic doodles.

As mentioned before, this is a simple app. You get exactly zero features, apart from being able to convert your signature from physical to digital form (in PNG format, I might add).

To finish the drawing and access the saving process, press any key, or click using the touchpad. Other things to be aware of include the fact that the app works for both X11 and Wayland. All desktop environments are supported in the case of X11, but only GNOME is supported at the moment when it comes to Wayland.

The easiest way to install the app (in my opinion) is directly from Flathub. For a more in-depth view of the app's installation options, feel free to visit the official GitHub repository (and maybe contribute if you find this app of worth to you).