Hi, I'm working on a small project. Its line art of a character. I'm trying to make the eyes a certain way. All I want to do is hide part of the iris (a circle) below the lines of the eyelid. I'll try to leave a picture Example If you can see my example picture, see how the X line cuts the circle into a half circle? This is how I want my eyes.

Draw a circle, then draw an 'eyelid' line across the circle, then manually erase the part of the circle that you don't want?

I'm not sure to understand what you want to do. If you want to hide part of you image, you have many ways to do that (erase, masks...). But it seems that you want something specific to a circle ? Your link point on too many images, maybe try to point on the specific image and it we'll be more clear.
Good luck !

Yes I want to use a mask. Do you know how I can do that? The link takes some time to load the example picture. Here is another example Example2. The second circle (blue and green circle) is a perfect example of what I'm trying to achieve. It has something to do with alpha inheritance which I'm unfamiliar with.

If you want to limit painting to an already existing coloured (drawn/painted) region, then 'alpha lock' is the simplest way to do this. 'Alpha inheritance' is more complicated to use.

However, you say you are producing 'line art' and want a particular shape for an iris, of an eye. Can you make a sketch of the effect you are trying to get?

Here's a simple one I made using layers, ellipses, circles and the flood fill tool: https://imgur.com/qz9Djoq
It has several flaws if you look closely.

Here is the sketch I am making. Here is an example of what I'm trying to achieve.
@ahabgreybeard That's a perfect example of what I am trying to achieve. I tried using Alpha lock and I didn't get the results I wanted.

I would suggest you do as follows:
Complete your lineart so there are no gaps and maybe add some pupils to the eyes. There is a large gap in the fur under the ear on the left side. I think you have a gap at the bottom of the ear on the right side. Any gaps would result in colour bleed when you use the flood fill tool.
Hide Layer 1 so your lineart is black on a transparent background then Export as a .png file.

Open the png file and give it a white background layer, or whatever colour you want, as a background layer.
Now you can 'play' with this new single layer lineart image without affecting your original lineart work.

Use an eraser to carefully remove the irises outside of the eyes.
For each region that will be a different colour, add a new paint layer with an appropriate name, under the lineart layer.
In each of these 'colour layers', use the flood fill tool with its options set to Limit To Current Layer-unchecked and Grow Selection by 1px. (You can undo at each stage and try different amount again).
If the flood fill tool bleeds out, undo the operation and fix the lineart gaps.
Then you can colour each region in the colour of your choice, iris, whites, pupil, nose, fur, ears.

Then in each colour layer, click the right side icon (checkerboard cross) which is the 'alpha lock' icon, to activate it. Alpha lock is quite simple actually but you need isolated regions of colour, in different layers for easy use.
Then in each layer, you can add texture, highlights, etc. to your base colour with no danger of your texture brushwork affecting anything outside the existing coloured region.

There are more sophisticated ways to do region colouring and use 'alpha inheritance' to limit the application of textures and highlights but this way is very simple and easy to do.

Good luck and please let us know how it turns out.

So I followed your instructions. I filled in the outlines so the color wouldn't bleed out. I didn't make paint layers because I was confused how they work. Are paint layers like normal layers except they are only for paint? updated picture I also decided to use the eraser tool to erase the top parts of the iris, like you said. It worked out pretty well.

Yes, paint layers are 'normal layers', not vector, not transform, not etc. All the layers you are using in your original file are paint layers. You can tell by the small symbol at the left of the layer in the layer docker.

You seem to have now applied coloured regions to your original lineart work. This may cause problems if you want to make changes to your lineart in the future.
It's a very good idea to keep your lineart and your colouring work separate. This is why I suggested that you export the lineart to a .png file and do the colouring work after opening the .png image file.

It's also a good idea to have different layers for different coloured regions so that you can use 'alpha lock' to isolate any texturing/highlighting/ effects that you want to do on the fur, nose, eyes, etc.

The eyes are looking good. I'm sure you'll achieve good results with your final artwork.

Sorry it took me a while to see your answer. Ahabgreybeard already answered, and you found how to erase the iris, but I'll try to resume what your problem was for future reference, and maybe it will learn you some new things too :
1. on you lineart, you want to hide the part or the iris ellipse that comes out the eye shape
2. Then you want to add color to that
In my explanations I separated the two processes : linart and coloring, assuming that you could want to get a perfect lineart before beginning the color process.

For the first point, you can :
--> manually erase the lines you don't want : you can do that with an erase brush, or you can use this trick : take the lasso selection tool, define the region around the lines to erase, then erase with the brush (this technique I use often because I have complete control on what I'll erase). Note that this technique is "destructive" : if you change the eye shape in the future to make it bigger, you'll have to redraw the limits of the iris too

--> Use the alpha inheritance. With the fill tool, you fill the eye shape with your background color. You press Ctrl+Shift+G to create a group with alpha inheritance. On the new layer created (called "Mask Layer"), you can draw the iris : it will only appear on the filled zone of the eye. At this point it is not "destructive" : if you change the eye shape, the iris will still fit perfectly because the ellipse is still complete, just masked outside the eye shape. Later in your process, to get a perfect lineart, you will finally get rid of the unwanted iris lines : merge the too layers => obtain the good drawing on a single layer BUT filled with you background color. Make Filter>Color>Color to alpha to make the intorior of your eyes transparent again.

--> Use masks feature. As I'm still a beginner I can't help you with that, but I'm pretty sure it's a good way to do it too.
--> Surely there are other processes too, that I don't know yet !

For the second point : I will not enter in details here, you can use the fill tool, choose the right tool options and fill all the regions of you lineart, on an other layer, of course. You can also use the new type of layer that exists in Krita 4 : New Layer > Colorize Mask. I used it only one time but it worked perfectly and it was easy to play with (I didn't even read the doc, just pressed all buttons ). With this last method, you can keep some minors gaps in your lineart, Krita will do its best to get it right anyway, it's awesome !
As already said : always apply your colors on one or several layers, but not on your lineart layers : these have to remain dedicated to the lineart ! Coloring a lineart is a very common subject, so you'll find plenty videos on youtube accessible to beginners. You want to search for the more recent one that include the Colorize Mask method in Krita 4.


Hope you did not fall asleep reading this post Please tell me if some things are not clear. Good luck !

Mumuett's suggestions are good ones and they are the more sophisticated methods of colouring lineart. Alpha inheritance with layers in groups has the advantage that you can isolate the diffent types of effects, such as texture and highlighting and not have them destructively modify the base colour or each other.

Using the simple methods that I described, I made this simple colouring and texturing example:

https://imgur.com/a/aIfmjAd

The .kra file is here (3.1 MB): https://www.dropbox.com/s/jqzmi2ok7d8ks ... 1.kra?dl=0

Perhaps mumuett could do something to show us the results of the more sophisticated methods?

P.S. I had to redraw the irises and pupils and there are some minor flaws in the lineart.

Yes, I trust more my methods, even if they are more sophisticated. The result can be more clear because you'll have more control of what you're doing. You'll have to learn how to use alpha inheritance (see this very good video : https://www.youtube.com/watch?v=q2HB57GeeVE) but it is worth the effort, even for a beginner. And I think it will be very interesting to learn the Colorize Layer method to apply colors too. So I don't know if @LaHomme is still there, but I highly recommend this method for colorization. Note that I'm still a beginner myself so it's not only for professionals ^^'

@ahabgreybeard : I hope @LaHomme doesn't mind, I made some screenshots of my process step by step using his/her drawing : https://www.dropbox.com/s/oi77j1tjcu8eo ... s.zip?dl=0
One day I'd like to learn how to make videos