How to make part of curve white? (when approached by black background)

[AnnN]

Hi, I need the part of the paddle that is lying on black background (boat) to be visible (=be white). But just that one part. 
I dont want a round end of the curve, thats why I dont want to start a new one. 
How to achieve that?

[GarryP]

Welcome to the forums @AnnN

If you don’t mind the exported result being rasterised then, in this case, you could set the Blend Mode for the paddle to Divide, see attached image.
If you need the exported result to be in vectors then you will probably have to resort to more labour-intensive measures such as expanding the stroke on the paddle and then using various geometry functions.

[AnnN]

Hi and thanks!

so when I use Divide it will be in raster right?

I'd like it to be in vector, so it probably gonna get complicated, but I will manage.

Also, how can I tell right away that its been rasterized? It looks same to me.
 

[GarryP]

Using a blend mode will usually (maybe always, I can’t remember off the top of my head) cause the software to rasterise the things, upon export, that are affected by the blend mode.
The software can display them in vectors while it has control of the vectors and the blend but once they go to be exported the software has less control over them and it has to rasterise some things to be safe.
It’s a good rule-of-thumb to remember that:

• Blend Modes;
• Adjustments;
• Effects;
• Filters;
• and some others;

all cause things to be rasterised (as of version 1.9.2/3).

[loukash]

3 hours ago, AnnN said:

I'd like it to be in vector

Create a compound object, use the Xor mode: