Years ago most concrete work was formed with standard materials. Sheets of plywood, four by eight feet, were the most common since they produced fewer joint marks to be finished than did smaller panels or boards. Today, however, an architecturally attractive wall can be formed economically by using form liners to prevent or obscure blemishes and at the same time provide an aesthetic texture. It is obvious that best results with the liners will be obtained when special attention is given to accurate form alignment, the sealing of joints against grout leakage and the use of quality concrete. Most form liners can be used with any forming system. They are particularly useful in large heavy-duty gang form sections because in these the joints can be permanently aligned and sealed. Form liners have been made from rubber, steel, wood, or plastic. Most liners today are plastic because plastic liners can readily be mass produced and because they offer possibilities for a wide range of designs, finishes, and textures to be achieved. Further advantages with plastic liners are that they allow intricate designs to be cast with very good resistance to water and chemicals. There are many types of ties available for architectural concrete. Patching tie holes with success in not easy because it is hard to match the finished color of the concrete and the patches tend to accent rather than conceal the holes. Many ties are supplied with cones of various depths which can be used to leave a clean, chip-free hole to patch. Some ties are tapered so that the ties themselves are removable. These have separate outer units for proper adjustment. If possible these ties should be removed from the unexposed side of the wall to prevent unnecessary chipping or breaking of concrete around the tie holes on the exposed side. If rustication strips are used, prior planning of the locations may permit ties to be placed within the strips so that the marks occur in the impressions where they are not as noticeable after stripping.