Just Mousing Around ~ Extreme Basics of PSP Masks

..: Extreme Basics of PSP Masks :..

Let's pretend it is the week before Christmas. It's dark and cold outside and you are bored beyond belief. (You are also broke and your Visa card is maxed out... but this is supposed to be a happy story, so we won't go there). Suddenly you have an idea... why not get out that can of fake snow that you bought (you know, that white gritty stuff that never completely comes off until around the third week of August) and spray some Christmas decorations on the windows? Excellent idea...

You give the can a good shake and, with long sweeping wrist movements, you attempt to draw a Christmas tree on the glass. Except that it turns out you are somewhat artistically challenged... and the tree you created looks more like an Egyptian pyramid in the aftermath of an earthquake measuring 9.8 on the Richter Scale. While the kids are having a hearty laugh at your expense, you suddenly remember that you also bought a package of stencils to help you with the finer points of aerosol dust art.

After much deliberation, you choose the star stencil... after all, if it was enough to lead the wise men on their journey, it should work well as a beacon to guide Santa to your living room. You tape the piece of WHITE cardboard to the window. The cutout of the star appears BLACK against the dark window pane. You take up the spray can with renewed confidence and spray away. When you lift the cardboard stencil off the window you have a perfect snow-filled star staring you right in the face. You are suffused (now there's a word you don't see often... thank goodness) with pride... the children gaze up at you in awed silence... it is a beautiful thing.

But is it a miracle? No... it is a simple mask.

If you think of masks this way... as just a stencil... it will take the mystery out of how they work. I emphasized the cardboard as being white and the cutout being black for good reason. When using masks, what is WHITE blocks out colour... and what is BLACK accepts colour. Just as the cardboard didn't let any canned snow touch the window.... the star cutout let it all through. I remember it this way... WHITE is virginal, pristine, untouchable... BLACK is lonely, empty and longs for colour.

Okay... but we are not in our living rooms armed with cans of fake snow. We are at our keyboards and have fired up PSP and want to see how masks work. So let's do that. We'll use a star mask and the airbrush tool and do exactly the same exercise here.

Right click on the star graphic below...

...and save it to your desktop so it will be easy to find and easy to trash when we are done. Then open it in PSP and increase the colors to 16 million. (Colors|Increase Color Depth|16 million colors) Because the star graphic is in 256 color .gif format, PSP won't let you make a mask out of it (not even if you toss in a bribe with your request) until you up the color depth.

Now let's make a mask (or stencil) out of this black and white graphic. Go to Masks|New|From Image. In the Add Mask window, the settings should appear thusly:

These are the default settings and will be used most of the time.

You will notice that an asterisk (in PSP7 you will see a mask icon) appears beside "Background" on the layers palette. This tells you that a mask is currently in use on that layer. Go to Masks|View Mask. The white area of your image becomes covered with a reddish hue, while the black star remains black.

This shows you the mask at work. The reddish color (like red Saran Wrap) is protecting the white areas... because WHITE rejects color (and stays fresher longer). The black area is left unprotected because BLACK welcomes color. Go back and click on Masks|View Mask again to turn off the view mode.

Now that you have made the mask (the stencil) you'll want to put it in a safe place (like on top of the fridge) until you can find the cellophane tape to mount it to the window.

Go to Masks|Save To Alpha Channel (I'm pretty sure that Alpha Channel means On Top Of The Fridge in some obscure techy language. And if it doesn't... it should.) Just click OK on both windows that pop up... let's be wild and crazy and accept everything without reading the fine print for now.

Okay... the mask/stencil is safely on top of the fridge where the cat can't shred it in the next 5 minutes or so. Click the minus sign on the mask window to minimize it. That last bit of info is very important. If you X out (close) the mask window, even though you saved it to the top of the fridge, your mask will disappear from the face of the earth and PSP will tell you there is nothing on top of the fridge when you go back to get it. Stuff that has been saved to an Alpha Channel is only available while the original window in which the stuff was created resides onscreen. This is true of both Selections saved to an Alpha Channel and masks. So just minimize the thing and ignore it. The alternative is to save your mask to disk, where it will reside forever until you remove it or have a crash... but it's not even a pretty star... and we don't want ugly star masks cluttering up our hard drives. (Not to confuse the issue further... we could also use this same window to complete the rest of the exercise, but I wanted to point out how saved masks and selections behave.)

Now we need a window to decorate. Your mask is 200 pixels X 200 pixels... so let's open a new window the same size. New Image... 200x200... and choose Blue for the background.

Add a new layer (Layers|New) and name it Star... or something equally intense.

With the Star layer the active layer (the layer button is pushed in as in the above picture... in PSP6 & 7 it will be highlighted instead) go to Masks|Load From Alpha Channel. In the window that pops up you will see your star mask... click OK.

Alllllrighty then.... your stencil has been duly scotch-taped onto your window pane. Grab your can of snow (airbrush tool). Set your foreground color to something that contrasts nicely (or horrendously, as the case may be) with the blue background so that you can easily see the next step as it unfolds. Set the controls on the airbrush tool as follows:

(A quick tip here... when working with masks, always max out your density, opacity and tolerance levels on the painting tools... otherwise you won't get the desired results)

Now spray over your mask any way you like. No need to be careful... everything except the star is protected from the paint. You will see that your new color is filling up the star shape, but leaving your blue background untouched. Ahhh... the magic of masks.... ;)

Got your star all painted? Now, just for the halibut, hover your cursor over the Star Layer on the layers palette (don't click) and have a peek at what's really on that layer.

Kinda Picasso-ish, eh? (Being Canadian, it was inevitable that I would have to say "eh?" at some point or another. Going on too long without an occasional "eh?" causes acute vernacular trauma in Canadians.. hehe..) So that's what the layer looks like without the mask. And that should tell you how to answer the next question you will be faced with. Cuz now we delete the mask (we are done with it... the star is wonderful... time to peel the carboard stencil off the window) by going to Masks|Delete. A box will pop up asking you if you want the mask merged with the layer. Now, if you say NO... you will get the (maskless) Picasso image that you saw when you put the cursor over the layer. If you say YES, the program will bind the mask information to the layer and you get to keep that cool star image. A no-brainer, right? Right. :)

Let's recap here for a sec... pay attention... there will be a pop quiz later.. ;)

You can make a mask out of any black & white graphic as long as the color depth is set to 16 million colors.
What is WHITE will not accept paint, snow or American Express. What is BLACK will allow whatever you throw at it to come through.
The original window that you used to create your mask must reside onscreen (minimized is fine) for the Alpha Channel info to be available to you.
You can view the mask (oh Ye of little faith) at any time by going to Masks|View Mask. You can even leave the view mode on while working with the mask if you prefer, but that's kinda like taking a bath with a wetsuit on... not quite as much fun.
If the finished effect is what you were after, say yes to merge the mask with the layer when you go in to delete the mask.

This should give you a very basic understanding of the way masks work in PSP. There are alot of variables which I have not touched on here... as well as other functions that can be performed with masks. It is my hope that this tutorial will give you a fundamental knowledge base to build on as you learn more advanced mask effects.