# How to apply complex hand-drawn mutes to gathers and combine 2D results?

When working with complex hand-drawn mutes, the number of control points can quickly grow to unmanageable numbers. If you have access to the *Image Gather Processing module*, then consider using a polygon mute instead. This workflow is useful for anyone without access to the polygon mute process.

Instead of creating a single polygon mute for the entire line, create multiple hand drawn mutes, applying each mute separately, and combine these muted volumes (using volume maths) so that each mute is only applied over a certain CMP range.

Because it works with CMP values, this workflow is limited to a single line at a time.

- Go to the
**Mute**tab and add a**New Hand Drawn Mute**(see*Manual Picking (Mute)*). - Pick mutes for
**first N traces**until an unworkable amount of control points appear. - Next, go to the
**Process**tab and add a**Mute Gathers**process (see*Mute Gathers*). - Apply
**Mute Gathers process**and select the previously picked mute to create*Muted Volume A.* - Return to the
**Mute**tab and add another**New Hand Drawn Mute.** - Pick mutes for
**second N traces**until the mute is unworkable. - Apply a new
**Mute Gather process**to create*Muted Volume B*. - Repeat these steps until mute has been picked over the line.

- Go to the
**Process**tab and add a**Volume Maths**process (see*Volume Maths*) - Use
**Volume Maths process**to combine the*Muted volumes*. - Click the blue "
**+**" button and add the mute gathers created earlier. - In the formula box, apply this equation:

if (cdp <= 300, v1, if (cdp <= 600, v2, v3, 1) )

This approach can be adapted for more sections by extending the formula, e.g. for 5 sections.

- v1 to CMP300
- v2 to CMP600
- v3 to CMP900
- v4 to CMP1200
- v5 rest of line

if (cdp <= 300, v1, if (cdp <= 600, v2, if (cdp <= 900, v3, if (cdp <= 1200, v4, v5) ) ) )