# Trails with background Transparency

**URL:** <https://discourse.processing.org/t/trails-with-background-transparency/17139>\
**Category:** Coding Questions\
**Created:** [January 17, 2020, 2:16pm UTC](https://discourse.processing.org/t/trails-with-background-transparency/17139 "2020-01-17T14:16:01Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![kll](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/kll/32/964_2.png) [@kll](https://discourse.processing.org/u/kll)\
**Post date:** [January 18, 2020, 4:28am UTC](https://discourse.processing.org/t/trails-with-background-transparency/17139/2 "2020-01-18T04:28:46Z")

</div>

even if different system, point might be same:

> [@Repeated alpha not reaching full opacity](https://discourse.processing.org/t/repeated-alpha-not-reaching-full-opacity/16890):
>
> Hello, I’m using a rectangle filled with white and a certain alpha value at the beginning of draw, and I would think that if done enough times that eventually the first thing drawn in setup would eventually be totally white. I’ve tested and it only becomes totally white if the alpha value is 128 or above. For example, see if with this code the red circle ever becomes fully white: float x0, y0; float angle0, angleC; float radius = 5; int bg = 255; int alph = 10; // try up to 127 void setup(…

```auto
background(0,alpha);

```

is NOT adding up as expected…

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