Being thus properly stretched the muslin is ready for sizing. The size usually employed, is that known as gilders', or clear size, which, if good, is preferable to any other. It is prepared from parchment cuttings, and is to be procured at a trifling cost, at shops where gilder's materials are sold. An excellent size is made from isinglass, which is most valuable where extreme purity of colour is necessary. The fine colourless gelatine, now very commonly sold, when dissolved and diluted to a proper strength, yields, also, a size well adapted for the preparation of muslin.,When the first coating of size is dry, it will be found that the muslin has slackened, and hangs loosely in the frame. It will, therefore, be necessary to extend the frame, so as again to tighten the muslin. A second coat of size must be applied, and when this is dry, the muslin must be again extended as before.,