# Strange G-mask halo **URL:** \ **Category:** Flame Questions\ **Tags:** action, gmask, batch\ **Created:** [July 10, 2026, 8:07pm UTC](https://forum.logik.tv/t/strange-g-mask-halo/14644 "2026-07-10T20:07:16Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![halflife](https://avatars.discourse-cdn.com/v4/letter/h/b9bd4f/32.png) [@halflife](https://forum.logik.tv/u/halflife)\ **Post date:** [July 10, 2026, 8:07pm UTC](https://forum.logik.tv/t/strange-g-mask-halo/14644/1 "2026-07-10T20:07:16Z")
Hey friends, I’m getting some weird hilighting in the softness of some gmasks. I can’t seem to track down where it’s coming from. I imagine someone here might know exactly what’s going on and the proper button to push to make this go away? ![Screenshot 2026-07-10 at 1.54.32 PM](https://us1.discourse-cdn.com/flex020/uploads/thedepartmentofexternalservices/original/2X/c/c428cd218c66baaf1d9d9501ecf799394dba5c96.jpeg) ![Screenshot 2026-07-10 at 1.54.41 PM](https://us1.discourse-cdn.com/flex020/uploads/thedepartmentofexternalservices/original/2X/a/a8a1e7d1d82ffbc18ffaa582787009027e5bfcfd.jpeg) Should look like (and it does in some of my comps…) ![Screenshot 2026-07-10 at 2.05.14 PM](https://us1.discourse-cdn.com/flex020/uploads/thedepartmentofexternalservices/original/2X/6/692f252b08a0d49e6e853d281dd7b14f79dfe869.jpeg) ---
**Author:** ![PlaceYourBetts](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.logik.tv/placeyourbetts/32/6852_2.png) [@PlaceYourBetts](https://forum.logik.tv/u/PlaceYourBetts)\ **Post date:** [July 10, 2026, 8:29pm UTC](https://forum.logik.tv/t/strange-g-mask-halo/14644/2 "2026-07-10T20:29:18Z")
This looks like an unpremultiply error. The edge pixels are getting divided by the values coming from the gmask as if they had been multiplied by the matte. If they haven’t been multiplied by the matte then there is no need to do the unpremultiply (divide). Are you doing the comp in batch? Using an action node or a comp node. Can you share a grab of you schematic? ---
**Author:** ![PlaceYourBetts](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.logik.tv/placeyourbetts/32/6852_2.png) [@PlaceYourBetts](https://forum.logik.tv/u/PlaceYourBetts)\ **Post date:** [July 10, 2026, 8:43pm UTC](https://forum.logik.tv/t/strange-g-mask-halo/14644/3 "2026-07-10T20:43:40Z")
I suspect you are using action. Most unpremultiply techniques are quite explicit. Action is a little hidden away inside of the surface settings. Select the layer inside the Action schematic. Go to the **Surface** menu. Look for the **Blending** column or the **Alpha** settings (not in front of the box atm) You can toggle the setting between **Premultiplied** and **Unpremultiplied** (or “Straight”). If you are getting dark or white edges, ensure this is set correctly to match your source material. ---
**Author:** ![Ryland](https://avatars.discourse-cdn.com/v4/letter/r/ba8739/32.png) [@Ryland](https://forum.logik.tv/u/Ryland)\ **Post date:** [July 10, 2026, 8:49pm UTC](https://forum.logik.tv/t/strange-g-mask-halo/14644/4 "2026-07-10T20:49:39Z")
If you can rule out premultiplication errors, then I would attribute this to a known bug that can present similarly. It can usually be resolved by pre-rendering your mask. ---
**Author:** ![halflife](https://avatars.discourse-cdn.com/v4/letter/h/b9bd4f/32.png) [@halflife](https://forum.logik.tv/u/halflife)\ **Post date:** [July 10, 2026, 8:52pm UTC](https://forum.logik.tv/t/strange-g-mask-halo/14644/5 "2026-07-10T20:52:14Z")
Yes, working in action. I tried toggling the premultiply button. Super familiar with that setting… Sorry for the messy scematic! The funny thing is I think I fixed this on one of the other comps but for the life of me can’t remember what I did… ![Screenshot 2026-07-10 at 2.46.24 PM](https://us1.discourse-cdn.com/flex020/uploads/thedepartmentofexternalservices/original/2X/8/89903a54f8d495dd98ff7d4cf7a516d885d98b96.jpeg) ![Screenshot 2026-07-10 at 2.45.57 PM](https://us1.discourse-cdn.com/flex020/uploads/thedepartmentofexternalservices/original/2X/0/07febe7f83565749e1a68d084b84ac0a678869e1.jpeg) ---
**Author:** ![halflife](https://avatars.discourse-cdn.com/v4/letter/h/b9bd4f/32.png) [@halflife](https://forum.logik.tv/u/halflife)\ **Post date:** [July 10, 2026, 8:57pm UTC](https://forum.logik.tv/t/strange-g-mask-halo/14644/6 "2026-07-10T20:57:25Z")
Ah… that makes sense. Googling how to pre-render a mask… Thank you! ---
**Author:** ![BrittCiampa](https://avatars.discourse-cdn.com/v4/letter/b/ec9cab/32.png) [@BrittCiampa](https://forum.logik.tv/u/BrittCiampa)\ **Post date:** [July 10, 2026, 9:06pm UTC](https://forum.logik.tv/t/strange-g-mask-halo/14644/7 "2026-07-10T21:06:04Z")
Just out of curiosity, what are these three gmasks masking? Especially on surfaces 2 and 3? ![image](https://us1.discourse-cdn.com/flex020/uploads/thedepartmentofexternalservices/original/2X/9/97a779b81495dbb3505782788607b6422f779f7d.png) ---
**Author:** ![halflife](https://avatars.discourse-cdn.com/v4/letter/h/b9bd4f/32.png) [@halflife](https://forum.logik.tv/u/halflife)\ **Post date:** [July 10, 2026, 9:22pm UTC](https://forum.logik.tv/t/strange-g-mask-halo/14644/8 "2026-07-10T21:22:15Z")
So… Surface 3 was a remnant of a previous thing that I did and I hadn’t deleted it yet. It isn’t doing anything and I’ve deleted it to no effect. Surface 2 is the front of the basket that is rotoed out to cover the dog that we’re adding into the shot. ---
**Author:** ![halflife](https://avatars.discourse-cdn.com/v4/letter/h/b9bd4f/32.png) [@halflife](https://forum.logik.tv/u/halflife)\ **Post date:** [July 10, 2026, 9:24pm UTC](https://forum.logik.tv/t/strange-g-mask-halo/14644/9 "2026-07-10T21:24:37Z")
This is without surface 2… ![Screenshot 2026-07-10 at 3.24.25 PM](https://us1.discourse-cdn.com/flex020/uploads/thedepartmentofexternalservices/original/2X/5/50b020a2070fb2aa3917485dd5df3458dad28fd5.jpeg) ---
**Author:** ![BrittCiampa](https://avatars.discourse-cdn.com/v4/letter/b/ec9cab/32.png) [@BrittCiampa](https://forum.logik.tv/u/BrittCiampa)\ **Post date:** [July 10, 2026, 9:38pm UTC](https://forum.logik.tv/t/strange-g-mask-halo/14644/10 "2026-07-10T21:38:42Z")
So this might help two birds and one stone- I would do that restore roto (surface 2) outside of the action in just a gmask tracer. Gmasks in action slow you down and with your selective and stuff happening in there I wouldn’t be surprised if somehow that’s busting some premult thing. I’m not here to tell anyone how to comp, Flame is very flexible, me personally, I’d go about it something like this though. The part that really might help though is the BasketRestore happening outside of action. So the order being, BG Plate, Dog, Basket over top )the comp action is just layering things, only premultiplied surface is the dog). I 100% don’t want to sound condescending by the way!! Just a thought about things happening in action or outside, totally personal preference though! ![image](https://us1.discourse-cdn.com/flex020/uploads/thedepartmentofexternalservices/original/2X/a/a8577e39d4bdc2bde1543bd366f0f4d7c1806a72.jpeg) ---
**Author:** ![halflife](https://avatars.discourse-cdn.com/v4/letter/h/b9bd4f/32.png) [@halflife](https://forum.logik.tv/u/halflife)\ **Post date:** [July 10, 2026, 10:25pm UTC](https://forum.logik.tv/t/strange-g-mask-halo/14644/11 "2026-07-10T22:25:33Z")
Thank you for the awesome tip! I can definitley see how this workflow would optimize a lot of what’s going on.