In this tutorial I explain the basic technique of masking. With masking you can remove a shape from an existing image. You can use this to insert shapes into already drawn backgrounds. You can create a small white border around text or add an exact shadow to a shape.

I worked inaccurate in for the example pictures in this tutorial. The selection for inverting the whole page was not exact the same for both invert operation. Because of this you see wrong pixels at the border of the pictures. Be careful with your own Flipnotes.

Make sure you create a copy of the background before you do masking. If something goes wrong you can just reuse the copy of your background.

Cut Out a Shape From a Layer

  1. Here you see the layer from which we cut out a shape.
    Masking 001
  2. This is the shape we place on the layer.
    Masking 002
  3. First we have to prepare a mask. A mask is a layer in which every pixel which shall cut is black. In our case, I could simple fill the outline with black.
    Masking 003
  4. Next we invert the whole page with the background. Best is to draw a rectangle selection over the whole page.
    Masking 004
    1. Choose the selection tool.
    2. Press and hold Start and Select.
    3. Move your stylus from the top left corner to the bottom right corner of the screen of your DSi. In many cases you can not select the entire screen. This is not necessary at all, but you have to make exact this selection twice. So first test if you always get the same rectangle that way.
    4. Let go of Start and Select.
    5. Press and hold [L], and press once Ⓧ (or [R] and 'up' on the D pad if you are using left handed settings)
    6. The screen is now inverted.
  5. Go to the page tools, copy your mask and merge it with the inverted background.
    Masking 005
  6. Now invert the background again as described in step 4 above. Make sure you select exact the same rectangle you selected at step 4, otherwise you possibly get artifacts at the borders (Maybe you can just erase them).
    Masking 006
  7. Now you are done cutting out the mask from your background layer. If you merge the initial picture (step 2) to the background with this gap, it looks like this:
    Masking 007

Make an Exact Shadow

To create a exact shadow for a shape, you use a slightly variation from the steps above.

  1. Prepare everything as described in step 1-3 in the "Cut Out a Shape From a Layer" section.
  2. Make an additional copy of your mask, and move this page e.g 8 pixels down and right. This will be the shadow and you can decide how far your shadow is away be use different movements.
    Masking 008
  3. Merge the moved mask with the background page.
    Masking 009
  4. Invert the background page.
    Masking 010
  5. Copy the initial mask (not moved) and merge it with the inverted background.
    Masking 011
  6. Invert the background page.
    Masking 012
  7. Merge the shape with the background.
    Masking 013

More Effects Using Masking

Gaps Around a Figure or Text

To create a small gap around the figure (or text), you just have to make the mask 1 pixel larger than the original figure is. To do this just copy the mask several times by 1 pixel shifted on a page. I use this steps to create a 1 pixel larger mask:

  1. Create an empty page.
  2. Go to the page with the mask.
  3. Select the mask.
  4. Copy the selection.
  5. Go to the empty page.
  6. Insert the selection.
  7. Press Ⓐ to make a stamp.
  8. Press and hold [L] and don't let it go until the end of this list.
  9. Press once ↑ (on the D-Pad) to move the selection one pixel up.
  10. Press Ⓐ to make a stamp.
  11. Press once →, press Ⓐ to make a stamp.
  12. Press once ↓, press Ⓐ to make a stamp.
  13. Press again ↓, press Ⓐ to make a stamp.
  14. Press once ←, press Ⓐ to make a stamp.
  15. Press again ←, press Ⓐ to make a stamp.
  16. Press once ↑, press Ⓐ to make a stamp.
  17. Press again ↑, press Ⓐ to make a stamp.
  18. Let go [L].

Now you have a mask which is at every point 1 pixel wider.