mostly evolved to make paper as quickly as possible, with labor being divided and specialized and new tools and ingredients added towards this end. Almost all production facilities are family based, but the level of organization varies. Most paper making is done inside the home by those who are dedicated to it either full or part-time. If the paper is made only part-time, then the work is done sporadically and usually only by women and children. A more recent phenomenon is the development of large workshops which hire artisans to do the work, supervised by the family which owns the enterprise. These are often established by families who have invested money sent home by migrant worker into materials and equipment. Most of the production of all these facilities is plain sheet of 40 cm by 60 cm, but the larger workshops make the greatest variety of products including giant sheets of 1.2 by 2.4 meters in size. Ecological concerns The commercialization of amate paper has had negative environmental effects. In pre-Hispanic times, bark was taken only from the branches of adult trees, allowing for regeneration. Ficus trees should be optimally no younger than 25 years old before cutting. At that age the bark almost peels off by itself and does less damage to the tree. Other trees such as mulberry do not have to mature as much. The pressure to provide large quantities of bark means that it is taken from younger trees as well. This is negatively affecting the ecosystem of northern Puebla and forcing harvesters to take bark from other species as well as from a wider range, moving into areas such as Tlaxco. Another problem is the introduction of caustic soda and other industrial chemicals into the process, which not only gets into the environment and water supply, can also directly poison artisans who do not handle it properly. Fondo Nacional para el Fomento de las Artesanías, the Universidad Autónoma Metropolitana-Iztapalapa, the Universidad Veracruzana and the Instituto de Artesanías e Industrias Populares de Puebla have been working on ways to make amate paper making more sustainable. One aspect is to manage the collection of bark. Another is to find a substitute for caustic soda to soften and prepare the fibers without losing quality. Not only is the soda polluting, it has had negative effects on artisans' health. As of 2010, the group has reported advances in its