each stroke is pretty much identical, unless I comically push hard or
This sounds like it might be an issue with the pressure curves - the thing the software uses to translate X amount of pressure you put on the pen to Y amount of stuff on the page.
- Sometimes you can edit pressure curves in pen tablet software you installed with the tablet drivers you installed when you set it up (e.g. Wacom tablets have a 'manager' application that lets you tweak this and other things.
- If you don't have the right drivers, it'll go a bit haywire. This could be your problem - make sure they're up to date, for the right product version and operating system version, etc etc.
- Sometimes the drawing program itself lets you adjust the pressure curves (e.g. Infinite Painter for Android lets you do this for each brush).
It's to allow you to set it up to match your drawing style. For example, I tend to use softer pen strokes than other people, so I always set up whatever I use to have a steeper curve that is more sensitive to lower amounts of pressure (so, more responsive to light touches) and needs less pressure to reach maximum.
If that sounds confusing, I just found this explanation in comic form.
Also be aware that some pen tablets are just a bit rubbish with pressure curves. If it's not a well made tablet, it'll still give blotchy even after you've tweaked the pressure curve. I think there are some makes of tablet that don't even allow you to adjust the curve like this.
But in videos such as this it seems effortless for the artist to have beautiful, varying widths. How is this accomplished?
The answer here is pressure sensitivity, and for pressure sensitivity to work, every step in this chain has to work (most of the time it pretty much works out of the box):
- Your drawing tablet has to actually support pressure sensitivity. Any drawing tablet aimed at artists and designers will, but there are some (e.g. ipad-style touchscreens that are prodded with a stick or a finger) that don't have the right tech built in to do any kind of pressure sensitivity.
- As Lotto says the drivers need to be set up properly. These are usually specific to the make of drawing tablet. They take the pressure data from the pen and translate it into something that other applications on your computer can understand.
- You need a drawing application that knows how to use pressure sensitivity data from drawing tablets. Most proper digital art applications do (e.g. Photoshop, Artrage, Sketchbook, Photoshop Elements), but there are probably some that don't - check. It's also possible that some specific drawing applications don't support pressure sensitivity from some makes of drawing tablet.
In whatever drawing application you use, you need to be using a brush that maps pressure sensitivity to line width.
- In most good drawing applications, pressure sensitivity can be mapped to a range of things like line width, opacity, colour, scatter of pattern brushes, etc etc. Photoshop has heaps of options like this in brush settings - poke around.
- In some applications (e.g. art brushes and blob brushes in Illustrator), options like this exist, but the default is nothing and you have to set it manually.
- In other applications (I think Artrage and Sketchbook are like this), they use analogies to physical drawing tools and make you guess/figure out what does what - e.g. an 'ink brush' or 'drawing pen' might map pressure to width while a 'pencil' or 'airbrush' might map pressure to opacity, and some brushes won't use pressure at all.
Any one of these not being set up right will stop it working, so if you're not getting pressure sensitivity when you draw, check each one of these in turn.