To Prevent Electrotype Blocks from Warping.
To prevent electrotype blocks from warping, shrinking or swelling, place them in a shallow pan or dish, cover with kerosene oil and let them soak as long as possible, say three or four days. Then wipe dry and place in the form. After the first two or three washings they may swell a little; if so, have them carefully dressed down, and after that you will have little or no trouble with them, and can leave them in the form just as you would were they solid.