Unpaintable streaks in Weight Paint Mode

Question

I am new to blender and am currently trying to rig and animate a model of a simple cartoon duck. After creating an armature and assigning it to the model however, I found the automatic weights given were inappropriate, so decided to attempt to fix them using weight painting.

Once of the changes in particular that I wanted to make was to have the flat foot of the duck be fully affected by the foot bone. My problem is this: when trying to paint the foot all red, I get these strange blue streaks appearing:

I have tried painting over them with mixture/add brushes, with and without "limit selection to visible" checked, but it does not seem to make a difference.

Am I painting the weights incorrectly? Is it something to do with the way I have set up my armature or mesh? How can I solve this problem?

For reference:

• Vertex view of foot

• Wireframe view of foot

Answer 1

Those streaks are normal. They are caused by the way the paint display works. You are acutally painting on the vertices, not the faces. as a result, you will see unwanted blue areas on some of the surrounding faces.

Answer 2

The streaks that you are talking about is fine, that's just how blender shows it because you painted on the vertices the surroundings may create streaks as shown from your screenshot I wouldn't worry about it, its normal and common.

A recommendation is you could select the face itself, go to the vertices tab in properties and assign what you have selected to the amount of weight you want. This way it will be much more neater and more preferable to the display you want.