Fencing is a necessary but expensive forest management operation. While it is possible to erect a fence that is completely effective against any animal, this is usually too costly. Any forest fence is a compromise between expense and effectiveness. The introduction of spring steel wire by the Forestry Commission into the construction of forest fences in 1969 substantially reduced costs compared with traditional forms of fencing using mild steel wire. The main advantage of spring steel wire is that once it is strained it will remain taut. This allows stakes and straining posts to be widely spaced, so requiring less material and labour without reducing the effectiveness of the fence. Small economies have been made by using spring steel wire for multi-strand and dropper fences but the most suitable application and the greatest economies are in the use of this wire to support wire netting. Further savings have been made by introducing improved methods of working and labour-saving tools. Improvements to the design and construction of fences are constantly under review. In the 23 years since 1969 new and improved materials, tools and working practices have been introduced. Any savings obtained can be wasted if the initial planning of the fence has not been thorough. The specification of the materials to be used must be consistent with the period and the purpose for which the fence is required. The amount of material required can be reduced and the problems of negotiating natural obstacles can be avoided by careful siting.