Normally, you'd use something like: glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); glEnable(GL_BLEND); glEnable(GL_LINE_SMOOTH); glLineWidth(2.0f); glVertexPointer(2, GL_FLOAT, 0, points); glEnableClientState(GL_VERTEX_ARRAY); glDrawArrays(GL_LINE_STRIP, 0, num_points); glDisableClientState(GL_VERTEX_ARRAY); It looks good in the iPhone simulator, but on the iPhone the lines get extremely thin
![OpenGL ES iPhone - drawing anti aliased lines](https://cdn-ak-scissors.b.st-hatena.com/image/square/98d6f053a97a87156775f60757c60865d0f2c47d/height=288;version=1;width=512/https%3A%2F%2Fcdn.sstatic.net%2FSites%2Fstackoverflow%2FImg%2Fapple-touch-icon%402.png%3Fv%3D73d79a89bded)