<p>The purpose is to prepare a flake for improved manipulation.</p>

<p>Abrasion is a process also referred to as '<em>raking</em>': </p>

<blockquote>
  <p>Raking is the action of carefully dragging a course abrader or other device <strong>to remove "micro" flakes from the edge of a biface or preform</strong> to change it's [sic] shape or give support to an edge before actual abrading is done prior to percussion or pressure work.<br>
  <sup><a href="https://www.flintknappingtools.com/terms.html" rel="nofollow noreferrer">source</a></sup></p>
  
  <p>Edges being worked [especially while soft hammer knapping] must be ground dull prior to flake removal. <strong>This dulling helps prevent edge collapse</strong>. A piece of sandstone, very soft limestone, or other soft rock may be used to dull the edge.<br>
  <sup><a href="https://archaeology.uiowa.edu/flintknapping-0" rel="nofollow noreferrer">source</a></sup></p>
  
  <p>The process [of lithic reduction] also involves frequent preparation of the edge <strong>to form better platforms for pressing off flakes</strong>. This is usually accomplished with abraiders made from a coarse-grained stone such as basalt or quartzite.<br>
  <sup><a href="https://en.wikipedia.org/wiki/Lithic_reduction" rel="nofollow noreferrer">source</a></sup></p>
</blockquote>

<p>Essentially, the abrasion allows for the force to be distributed more evenly and controllably.</p>

CC BY-SA 4.0
2020-03-04T11:58:11.453Z
2020-03-04T11:58:11.453Z
Joachim
<p>I'm trying to learn flint knapping, and I keep seeing references to abrading the edge while working the material.</p>

<p>What is the purpose of doing this?  How do I know when an edge should be abraded, and how do I know when I have abraded it sufficiently to go back to pressure flaking?</p>

CC BY-SA 3.0
2017-02-12T13:40:34.143Z
@Willeke -- I was sort of torn about your edit, but it includes a partial answer (abrading is done "to strengthen the [edge] in preparation for flake removal") and I think it would be better added as an answer.
Erica
<lapidary><knapping>
What is the purpose of an abrader in flint knapping?
Beofett
# What is the purpose of an abrader in flint knapping?

(Asked by: username_0 on 2016-04-26)

I'm trying to learn flint knapping, and I keep seeing references to abrading the edge while working the material.

What is the purpose of doing this? How do I know when an edge should be abraded, and how do I know when I have abraded it sufficiently to go back to pressure flaking?

**Tags:** lapidary, knapping

> **Comments:**
> **username_1**: @Willeke -- I was sort of torn about your edit, but it includes a partial answer (abrading is done "to strengthen the [edge] in preparation for flake removal") and I think it would be better added as an answer.  

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## 1 answers

### Answer by username_2 on 2020-03-04. Score: 3

The purpose is to prepare a flake for improved manipulation.

Abrasion is a process also referred to as '*raking*':

> Raking is the action of carefully dragging a course abrader or other device **to remove "micro" flakes from the edge of a biface or preform** to change it's [sic] shape or give support to an edge before actual abrading is done prior to percussion or pressure work.  
> [source](https://www.flintknappingtools.com/terms.html)
>
> Edges being worked [especially while soft hammer knapping] must be ground dull prior to flake removal. **This dulling helps prevent edge collapse**. A piece of sandstone, very soft limestone, or other soft rock may be used to dull the edge.  
> [source](https://archaeology.uiowa.edu/flintknapping-0)
>
> The process [of lithic reduction] also involves frequent preparation of the edge **to form better platforms for pressing off flakes**. This is usually accomplished with abraiders made from a coarse-grained stone such as basalt or quartzite.  
> [source](https://en.wikipedia.org/wiki/Lithic_reduction)

Essentially, the abrasion allows for the force to be distributed more evenly and controllably.


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