CLIP STUDIO PAINT has a very useful layer called the "vector layer",
which differes greatly from raster layers.
This time, I will show you how to use it.
First, I'm opening the [Layer] menu, click [New Layer] and then [Vector layer...] to create this type of layer.
In the Layer palette, you can distinguish the layer types by their icons.
Just like on an ordinary raster layer, you can still draw on it....
...by selecting a drawing tool, like the [Pencil] and putting down a line.
However, editing and processing lines on a vector layer is done by
using dedicated vector editing tools and the [Object] tool.
For example, you can easily select and move lines you don't need with it.
By using the "Operations" in the [Tool Property] palette and checking "Select multiple by drag",
you can select multiple lines at once.
You can then scale them up or down and rotate them without deteriorating their quality.
Now, let's try inking something on the vector layer.
A vector layer can also be created by clicking on the vector layer icon in the [Layer] palette.
I will choose a pen and then draw the outlines of the character.
Even if there are many protruding lines like in this case,
these can be easily erased on a vector layer.
After choosing [Vector] from the [Eraser] tools and activating [Erase up to intersection] in the [Tool property] palette...
...simply draw over the lines that protrude to erase unnecessary parts.
As before, you can edit parts of the drawn lines with the [Object] tool,
or use the control points individually to make corrections.
It's also possible to modify the line width.
Activate "Thin width" of the [Correct line width] sub tool under the [Correct line] tool.
With this you can thin the lines just by tracing over specific parts of them.
Likewise, if you want a line thicker,
activate "thicken width" to make lines thicker by a specified amount.
If you want to change the entire line, you can do that with the [Object] tool,
and after selecting the line to edit, simply change the "Brush size" slider in the [Tool Property] palette.
Also, by clicking the "Brush shape" drop down menu just below that,
you can select a different type of brush shape registered with CLIP STUDIO PAINT to add texture to the line.
You can also register a line with varying strength yourself, so if you have a favorite pen, try registering it.
Select your favorite pen and open the [Sub Tool Details] palette and [Brush shape].
The registration is complete when the [Register all settings to initial settings] button is clicked,
while the brush shape is selected.
The registered brush shape can now be used.
Some tools such as the [Fill] tool can not be used on a vector layer.
Should you try to use the [Fill] tool, the "restriction" mark is displayed when hovering over the canvas.
For this case, you have to use a raster layer to use the fill tool.