The Classic canvases are eraser-proof. Under the following conditions, you can remove sketches without leaving any residue.
Canvases of the MHP Classic series are already optimally stretched on a sturdy wooden bars from sustainable forestry. Before you start to paint the canvas, you do not have to stretch anything.
Only with a finished painting on canvas this point could become interesting.
There can be various reasons why a painting needs to be re-stretched:
In these cases, the finished artwork can be re-stretched.
The painting on the canvas must be completely dry before you stretch the canvas.
To re-stretch a canvas you need a hammer, eight wooden wedges and some space.
With each Classic Stretched Canvas you get a bag with 8 wedges. Two for each corner of the frame. If you lose them, you can buy standard wedges from your local artist supply store.
The hammer does not have to meet any specific requirements. You should only be able to wield it well.
To stretch the canvas properly, place the painted, dry canvas on the front side. To avoid damaging the painting, place the canvas on a smooth, clean table with a cloth or on the back of a stable easel.
Now you can see the back of the canvas with the staples and the frame bars with slots in the corners.
Use a hammer to drive the clamping wedges into all corners.
To keep the canvas evenly stretched, you should gently tap the wedges into all 4 corners evenly, piece by piece. Also check again and again that the frame bars do not warp in one direction.