Article: “Size” is the adhesive material applied to the surface that makes the copper leaf stick to it. There are two options available – water-based or oil-based size. Oil-based size is the most traditional choice. Quick-dry oil size reaches tack (the required “stickiness” to adhere the copper leaf) in about two hours. It is meant to be used for small projects or whenever you have a limited time frame to work within. Slow-set oil size will reach tack in ten to twelve hours. It is intended for larger projects that require a lot of work time.  Water-based size is an alternative to the more typical oil-based size. It comes to tack within twenty minutes, and remains workable for about thirty hours.  Water-based size is not burnishable. If you plan to burnish the surface, use oil-based size. Adhesive size goes on wet. Use a paint brush to apply the size carefully to the surface. Even application is desirable for best results. Use the paint brush to work the size to an even coat as you spread it over the surface. Make sure you cover all areas that you want to gild. Copper leaf will not stick to a surface that does not have size on it. Once applied, you must give the size the proper amount of time to reach tack before applying the copper leaf. Tack times vary based on which kind of size you use. Following the correct tack time procedure will greatly affect the final look of your project. For the most professional looking results, read and follow the tack time instructions precisely. Gently run the back of your knuckle over a small area of the surface. Listen for a squeak sound, which indicates tackiness has been reached. If the size is still too wet to apply the copper leaf, it will come off on your skin. When it’s ready, it will feel sticky but will not come off on your skin. Monitor the size carefully and test the tack every half hour until it has been reached.  Once the size becomes too dry, you will have missed your opportunity to apply the copper leaf. It must be applied to a surface with proper tack. If you live in a very warm or dry environment, keep in mind that tack time may be reduced.
What is a summary of what this article is about?
Choose the right size for your project. Apply the adhesive size. Allow time for tack to develop. Test the tack.