Filling against curve

[ghope]

Apologies if this question has been answered or is naive. I am attempting to fill against a curve using two colors and am following these steps, all on a single layer.

1. Draw curve using color A (top color), antialiasing turned on.
2. Fill below curve using color B (bottom color), tolerance 84%.
3. Fill above curve using color A, tolerance 84%.

The result is still a bit more ragged than I'm hoping for. Am I going about this in the wrong way? Should I be working at a much higher resolution? The intended output is an 8.5 x 11 poster. Many thanks for any guidance or gentle criticism.

[Welsh Yellow Cheddar]

Hello, I think you are using aliased rendering when drawing your line. You must change it at the top.

[Pixey]

You could also:

 

1.  Draw your curve and fill the first color.

2.  Gaussian Blur.

3.  Fill the second half.

 

[Tactilis]

43 minutes ago, Welsh Yellow Cheddar said:

I think you are using aliased rendering when drawing your line.

I don't think so.

1. @ghope said they had antialiasing turned on

 

2. The high tolerance when they do: "Fill below curve using color B (bottom color), tolerance 84%"  will be selecting the antialias transition pixels and will fill them all with solid colour; hence the jagged appearance.

@Pixey has the best solution - but make sure you don't set the tolerance too high when you fill the second half.

[ghope]

 

Thank you, Pixey! That looks much better. Is there a way for me to achieve a sharp transition between the two colors?

 

20 minutes ago, Pixey said:

You could also:

 

1.  Draw your curve and fill the first color.

2.  Gaussian Blur.

3.  Fill the second half.

 

 

[Pixey]

1 hour ago, ghope said:

Is there a way for me to achieve a sharp transition between the two colors?

 

Not on one layer.

 

Here is an example using a couple of Plugins.

 

1. draw the line in its own layer.
2. Select the bottom of the line
3. Make a new layer and fill the blue.
4. Go back to the line and select, make a new layer and fill with 2nd color.
5 Uncheck the line layer.
6. On both colors use the Plugin Blur Blend set at about 27.
7. Use AA's Assistant on both layers until you see a sharper edge on both.
8.Then go to "outline' and change the color accordingly on both layers until it fills up.

 

[Pixey]

Here's how on one layer.

 

1. draw the line at #10.
2. Select the bottom and fill.  Duplicate and merge a few times.
3. AA's Assistant.
4. Select the top and fill.

 

[BoltBait]

Use 2 layers: