thanks fellas,
vic, for this effect is that the chips are cases as in this case small when it comes to making this technique a Japanese (for instance), every time you put the sponge where there already chipped noticeable relief and is not smooth as in the other, also the edges of the paint of one another is quite remarkable, as one can see that the metal is beneath the top color and which has jumped with a ridge, it is seen that the metal is at the same height or above the paint should be above, even if the aspect is very superior in the sponge of the salt.