diff --git a/docs/Rotation_Distance.md b/docs/Rotation_Distance.md
index 0d7c6c9b..c2411a8a 100644
--- a/docs/Rotation_Distance.md
+++ b/docs/Rotation_Distance.md
@@ -62,7 +62,11 @@ Then use the following procedure to "measure and trim":
 3. Extrude 50mm of filament with the following command sequence: `G91`
    followed by `G1 E50 F60`. Note 50mm as
    `<requested_extrude_distance>`. Wait for the extruder to finish the
-   move (it will take about 50 seconds).
+   move (it will take about 50 seconds). It is important to use the
+   slow extrusion rate for this test as a faster rate can cause high
+   pressure in the extruder which will skew the results. (Do not use
+   the "extrude button" on graphical front-ends for this test as they
+   extrude at a fast rate.)
 4. Use the digital calipers to measure the new distance between the
    extruder body and the mark on the filament. Note this as
    `<subsequent_mark_distance>`. Then calculate: