Next, we’ll colour the glass with a vertical four-colour gradient. Set the colours to the following: at position 35%, C = 18, M = 10, Y = 22, K = 0; at position 47%, C = 0, M = 0, Y = 0, K = 0; at position 80%, C = 13, M = 14, Y = 22, K = 0; at position 97%, C = 6, M = 3, Y = 7, K = 0. This gives us the basis of the glass colour. Add an inner glow to give the effect of a curved surface: select Effect > Stylize > Inner Glow, set the Mode to Screen, Opacity to 100%, Blur to 68 pixels and ensure that Center is ticked. I used the colour C = 5, M = 2, Y = 10, K = 0, experiment to get the best soft shape to the glass.
Now we’ll get started on the transparency. The Transparency palette has a great dropdown that controls the blending mode of all shapes in a similar way to in Photoshop. The options we will be concentrating on are Screen Multiply and Overlay, which when used with black-and-white gradients and a little blur can create some excellent effects.
Let’s create the glass’ top. Create an oval at the top of the glass. Fill it with a horizontal white-to-black linear gradient. Keep it selected and change the blending mode from Normal to Screen – this will get rid of the black. Set the transparency to 45% and put a Gaussian blur of three pixels on it to soften the effect.
Create an ellipse over the top of the glass so it sits just inside the bowl. Use the Pen tool to remove the point at the top of the ellipse then use the Direct Selection tool (the white arrow) to pull the top two Beziers towards their nodes. We should now have a shape that looks like half a glass of liquid. Create a radial gradient from bottom of the shape to the top, use these three colours: at position 0%, C = 0, M = 0, Y = 0, K = 0; at position 13%, C = 55, M = 90, Y = 60, K = 70; at position 100%, C = 20, M = 100, Y = 75, K = 18.