Danger Style in Pixelmator
Open Pixelmator and create a new document. I’m using 1800×1600 pixels for the size. After that select Pen Tool and create triangle with a little bit round edges. Fill the Layer with yellow color and use 35 pixels for the Stroke. Then go to Layer > Convert into Pixels.
With Pen Tool create a lightning and add a shadow as well.
Now let’s make the effect more real by applying texture. Set the layer’s Blending to Hard Light.
Click to layer ‘Shape‘ and go to Edit > Load Selection. After that go to Edit > Invert Selection. Select ‘Texture‘ Layer. With Magic Eraser Tool erase ‘Texture‘ Layer.