make lines thicker on already drawn object

[Krikor]

(04-01-2022, 01:49 AM)vespa6 Wrote: Can someone please explain this in a bit more detail, I have tried and cant get it to work - Im new to gimp, still learning, thank you

vespa6,
Without further details, it's difficult to know what your difficulties are.
Maybe you don't know where to find the filters used, in this case:

Gaussian Blur, you can find it through the menus: Filters - Blur - Gaussian Blur.... At first try the default values.

Curves tool, you access this via the menus: Colors - Curves.

If you can give more details of what you are trying to do and where you are having difficulties then it would be easier to give you some more objective assistance.

[eradicatore]

I used 

• select things with fuzzy select
  
• Select -> Shrink (by say 15 px)
  
• cut and paste to a new layer
  

If you want to grow (as post asks) then that's just below Shrink in the Select menu

[basdas]

But how do you undo the blur at the end?

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(12-31-2019, 05:37 PM)Ofnuts Wrote: If you used the path tool, it's only a matter of re-stroking with a wider line.

Otherwise, starting with this;



Apply a Gaussian blur:



Start the Curves tool, and make a diagonal across the white part on the right (which is the histogram of your blurred image)



Result:



The trick being to find the position/slope of the diagonal which is the best compromise between smoothness and blurriness.
You can use the Threshold tool instead (but you will have jagged edges)(Threshold is just Curves with a vertical drop). You can also use Levels.

[Ofnuts]

(12-18-2022, 08:27 AM)basdas Wrote: But how do you undo the blur at the end?

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(12-31-2019, 05:37 PM)Ofnuts Wrote: If you used the path tool, it's only a matter of re-stroking with a wider line.

Otherwise, starting with this;



Apply a Gaussian blur:



Start the Curves tool, and make a diagonal across the white part on the right (which is the histogram of your blurred image)



Result:



The trick being to find the position/slope of the diagonal which is the best compromise between smoothness and blurriness.
You can use the Threshold tool instead (but you will have jagged edges)(Threshold is just Curves with a vertical drop). You can also use Levels.

You don't. If you do it well, most of it is removed when you apply Curves, and what is left acts as anti-aliasing and makes the edges of the lines smooth.