.The TextStrokeTransparency property sets the transparency of the stroke, or outline, of rendered text. This property and
TextBox/TextStrokeColor3 determine the visual properties of the text stroke.
Text stroke is rendered before normal text and is simply 4 renderings of the same text in +/- 1 pixel offsets in each direction. Text stroke rendering works independently and identically to
TextBox/TextTransparency. Since text stroke is simply multiple renderings of the same transparency, this property is essentially multiplicative on itself four times over (e.g. a TextStrokeTransparency of 0.5 appears about the same as TextTransparency of 0.0625, or 0.5^4). Therefore, it’s recommended to set TextStrokeTransparency to a value in the range of 0.75 to 1 for more a more subtle effect.
Text Highlight Oscillation
This code sample oscillates a TextLabel’s TextStrokeTransparency so that it blinks the highlight of a text.