Problems following a photoshop article in popular photography magazine?

I used an article in the Jan. 2008 issue of pop photo titled "4 ways to save a face." The 1st time I used it, it worked great, but now I am having problems with the 1st part of the article titled "All-Over skin Smoothing." Instead of bluring the skin and smoothing the skin, it makes black streaks. This only happens on some of the pictures, or it works only on certain people in the images. These are the directions the magazine gives: 1)Duplicate your background layer by going to Layler>Duplicate Layer. Name it Blur. 2)Go to Filter>Blur>Gaussian Blur. Set the radius to 50, and click ok. 3)Add a black layer mask to the Blur layer. Holding down the Alt key(Option on a Mac), click the Layer Mask button. 4)Hit B for the brush tool. In the options bar, pick a medium-sized brush, and slide the brush's opacity down to 30%. Be sure that white is set as your foreground color and paint your subject's skin until it looks smooth and glowing. Any advise on what I am doing wrong?

Not all faces are just right for these settings. You may have to use less blur or a smaller radius for some and more of each for others. Then, play with the opacity on the blurred layer until you like the result. You may not even need to use the white brush.

Good luck. This is where the "art" comes into play. Report It

Are you painting in the layer instead of painting on the layer mask?