Div with a transparent cut out circle
94181
Transparent half circle cut out of a div
73150
TikZ: draw objects in transparent objects (3d)
125686
graphics with \setbeamercovered{transparent}
110134
Blender 2.8 - Transparent background
130412
Combining transparency
77072
HTML + CSS: Numbered list with numbers inside of circles
122340
Can you set a border opacity in CSS?
71733
Transparent Mesh when rendering
50881
How can I implement "cut outs" for lighting in OpenGL?
71893
How to create a transparent triangle with border using CSS?
120029
How to make an inverse transparent circle in CSS
154686
Transparent image background in beamer
130350
Concentric circles with CSS
145293
Making an image with a transparent background
155365
Set Alpha/Opacity of Layout
55640
draw a filled up circle
88840
TikZ — rounded rectangle with transparent holes and custom width of borders