> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ntop.com/llms.txt
> Use this file to discover all available pages before exploring further.

# How to Create Surface Masks

Follow the steps below to generate surface masks for covering exterior faces for remanufacturing.

## Step 1: Import CAD and Drag into Part Input of the Surface Mask block

<Frame>
  <img src="https://files.learn.ntop.com/lessons/how-to-create-surface-masks/FG_12_Import-CAD.gif" />
</Frame>

## Step 2: Select Surfaces you wish to mask

<Frame>
  <img src="https://files.learn.ntop.com/lessons/how-to-create-surface-masks/FG_12_Surfaces-to-Mask.gif" />
</Frame>

## Adjustable Inputs

<Frame>
  <img src="https://files.learn.ntop.com/lessons/how-to-create-surface-masks/FG_12_Surface-Mask-1.png" />
</Frame>

The thickness of the mask is measured from the normal face.

<Frame>
  <img src="https://files.learn.ntop.com/lessons/how-to-create-surface-masks/FG_12_thickness.jpg" />
</Frame>

The Overhang is the extension of the mask beyond the surface boundary.

<Frame>
  <img src="https://files.learn.ntop.com/lessons/how-to-create-surface-masks/FG_12_overhang.jpg" />
</Frame>

The Resolution is the smallest feature nTop will recognize.

<Frame>
  <img src="https://files.learn.ntop.com/lessons/how-to-create-surface-masks/FG_12_resol.jpg" />
</Frame>

The Clearance is the space between the final part and the mask surfaces.

<Frame>
  <img src="https://files.learn.ntop.com/lessons/how-to-create-surface-masks/FG_12_clearance-green.jpg" />
</Frame>