Draw curved line that clips text with transparency in Illustrator

Question

I am using Illustrator CS6 and I have some text and want to create a curved line from the bottom left of the text to the bottom right that has a uniform vertical curve to it. Then I want to clip the line so it splits the text with transparency. See the image below, this was done in PhotoShop just using the Eraser Tool to give you an idea of what I am trying to achieve. How can this be done in Illustrator CS6?

Answer 1

The easiest way to achieve this is to use a clipping mask. That's essentially a shape that masks your text: everything inside the shape stays visible, everything outside of it is hidden.

We'd like the shape of the mask to be that of, well, everything but a curved line. We can easily draw smooth curved lines with the Ellipse tool, but Illustrator can't use strokes in masks, only fills. We will need to Expand our stroke after we draw it.

1. Draw a large circle with a thick stroke and no fill. Holding Alt while drawing to draw from the circle's center may help placing it correctly;
2. Adjust the stroke width and the circle's position as needed;
3. With the circle selected, choose Object > Expand... and click OK in the dialogue that pops up;
4. Draw a rectangle that completely covers your text;
5. Open your Pathfinder palette: Window > Pathfinder;
6. Select both the rectangle and the circle and choose the last option in the Pathfinder: 'Minus Back';
7. With the resulting two-part shape still selected, choose Object > Compound Path > Make;
8. Select both the two-part shape and your text and choose Object > Clipping Mask > Make.

Tricky element here is that the masking shape consists of two separate parts: the top half and the bottom half. Illustrator can't use two shapes as a clipping path, so we'll have to make sure we convert the two shapes into a single so-called Compound Path before using it as a Clipping Mask.

Answer 2

A more elaborate way would be to actually punch out the curved line from the letter shapes. This has the downside that you will not be able to change the text or the curved line anymore, as this is a destructive operation.

1. Draw a large circle with a thick stroke and no fill. Holding Alt while drawing to draw from the circle's center may help placing it correctly;
2. Adjust the stroke width and the circle's position as needed; With the circle selected, choose Object > Expand... and click OK in the dialogue that pops up;
3. Select your text with the black arrow tool and choose Type > Create Outlines;
4. Ungroup the resulting group of letterform objects until there are no groups left;
5. Select all letterform objects and choose Object > Compound Path > Make;
6. Select your circle and choose Object > Arrange > Bring to Front;
7. Open your Pathfinder palette: Window > Pathfinder;
8. Select both the circle and choose the second option in the Pathfinder: 'Minus Front';
9. Ungroup the result and apply fills and strokes as you see fit.