vertex paint?

is there a way to get vertex painting to stay inside my brush?

vertex painting does stay within your brush. Try adding the wire to draw mode so you can see where they intersect, thus where the vertices are. each vertex can have a color.
the color blends between each connected, so if you have a black next to a white it will appear grey in the middle.
this makes it look like the color is bleeding, but it’s just the way it works

is there a good way to “draw” on a mesh?

uv texturing is the best way to do this…
do you know how yet>?

Yeah, but this potion really sucks with my current mesh.

i don’t understand

I am trying to color part of a mesh that is full of triangles and stuff that is terrible to work with. and the part is roughly a cone.

Yes venar303 is correct . Vertex painting assigns RGB values to vertices only, so if you have a low poly/vetex count the color you paint will not “stay inside” your brush .

You can however get more control over what you are doing by :

  1. Add a subsurf modifier and then apply it . This will give you a higher poly/vertex count to paint on and so will seemingly let you paint “inside” your brush . The higher the subsurf level applied the more vertices etc., but you should realize the performance of doing this depends on your computers capacities …

  2. Use the Face Select Mode in Vertex Painting by hitting the “F” hot key in Vertex Paint Mode . This will show you the wires so that you know where the vertices are (like venar303 suggested on turning on the wire display but this adds some functionalities) . In this mode you can only paint on the vertices of the selected faces - those unselected will not be painted on . And you will not get the “bleeding” that venar303 mentioned from non Face Select vertex painting . Also in this mode you can hide/reveal faces using the “H” and “alt-H” hotkeys to get areas out of the way etc. And you can also tab into Edit Mode to select linked mesh parts to hide/reveal them - for example Suzanne the monkey mesh’s eyes are not attached to the rest of the head so in Edit Mode you could hit “L” over them to select them, then invert the selection then hit “H” to hide the rest of the head, and when you tab back into Vertex Paint Mode and if you are in Face Select all you will see are the meshes for the eyes to paint on and the rest of the head will not be visible . If you hit “F” again the rest of the head will be visible without wires .

… This also works with the Weight Paint Mode as well BTW …