# Mask questions

**URL:** <https://forum.kirupa.com/t/mask-questions/261139>\
**Category:** flash\
**Created:** [May 23, 2008, 2:05pm UTC](https://forum.kirupa.com/t/mask-questions/261139 "2008-05-23T14:05:40Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![monk\_e\_boy1](https://avatars.discourse-cdn.com/v4/letter/m/35a633/32.png) [@monk\_e\_boy1](https://forum.kirupa.com/u/monk_e_boy1)\
**Post date:** [May 23, 2008, 2:05pm UTC](https://forum.kirupa.com/t/mask-questions/261139/1 "2008-05-23T14:05:40Z")

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Hi,

I have read as much as I can about masks, but I still have a couple of questions.

I am drawing a line chart, the line is a sprite.

Over this, each point is plotted as a sprite these are children of the line. These points change onMouseOver and have onClick etc.

This shows what I am trying to do, but at the moment I am using the background colour:

[http://teethgrinder.co.uk/open-flash-chart/gallery-data.php](http://teethgrinder.co.uk/open-flash-chart/gallery-data.php)

I would like to make the points hollow so they cut out the line below. So say I have a point at 5,5 currently the line will go to 5,5 and a child sprite is placed there. I would like to cut a hole out of the line so you can see the background grid through it.

I tried using a mask, but the mask erases both the line and the child.

Is there a way of drawing a circle with alpha 0 that ‘erases’ part of the line?

Can I somehow use the alpha of the child sprite to erase part of the line?

I think what I want to do is fill the mask with 0x000000 and punch out holes in it.

Or something.

Many thanks,

monk.e.boy