 <p>the controls have an opacity when moving which by default is set to 0.4. To prevent that you can do this: </p> <pre><code>canvas.item(0).set({ borderOpacityWhenMoving: 1 }); </code></pre> <p>As far as I know the control knobs cannot be changed. You'd have to change the function that actually draws the controls. This is done in the function drawControls which either uses strokeRect or fillRect depending on the settings to draw the controls. You should be able to change the function to draw a circle.</p> <p>hope this helps. </p>