Why is this happening and how can I make it all uniform?

In case you only want black lines without fill colour.

At first: hide the grid in menu --> View

• select all [Strg/Ctrl]+[A]
• if the fill color Icon (at the bottom of the Tool Bar) is not in front of the stroke color Icon -> press [X] (otherwise continue with next step)
• press the key [#]
• deselect all [Strg/Ctrl]+[Shift]+[A]

Ready

wnc,

Based on a different interpretation, if you wish to have just the strokes, just use stroked paths. But you ought to join the rounded part of the C to the straight horizontal part so the inner and the outer parts are both formed by a single path instead of three; as you can see the fill only shows within the rounded parts.

I believe you are disturbed by the checkered background, but that is just the Grid showing. In this case it is a good thing because it reveals that the C parts need to be joined.

You can hide the Grid in the View dropdown by clicking Hide Grid.

And what Mylenium said.

An open path with a fill will automatically be fille between the start and end points of the path.

Just create closed paths that you want to be filled and don't give them a stroke.

And create open paths with a stroke, but don't give them a fill.

The end points of your open paths are being automatically connected to produce a fill because you didn't create actual closed shapes. This of course only looks good on some shapes. In order to get consistent behavior you have to create actual fill areas for the letters as closed paths and then overly your other paths with the black strokes. This isn't something that can be achieved using just single instances of the artwork.

Mylenium