This work is talking about nanoparticles, and their properties. It is about their behaviour in different conditions, as well about their behavior when they are mixed and combined with other materials. There will be words about their physical, chemical and biological properties, but also about their relationship with environment and their influence on living world, meaning animals and people. The issue about toxicity and ecological acceptability of nanoparticles will also be discussed in this work. The thing that makes nanoparticles interesting are properties that they gain, but did not have them before while the particle were in bigger scale size. By that we mean on exceptional optical characteristics, behaviour in solutions and possibilities of conjunction, in modes that would not be possible with much bigger particles making the newly acquired materials with exceptional possibilities. If you add a really small quantity of nanoparticles into the paper, you can drastically upgrade some of their properties and even add some new ones, while we do not loose the original function and quality of the original paper. If we use this opportunities we can make paper sustainable to water, to bacteria or even have paper with disinfection and magnetic properties. Such enriched paper opens new opportunities in paper and packaging industry applications. Especialy if we talk about antibacterial and magnetic enriched paper. For example magnetic enriched papar could revolutionize the paper industry, since it is easy to control and keep track of the magnetic nanoparticles. In this work there will be some talking about some very interesting nanomaterials like self-cleaning and rewritable papers and ones that can be used for colorimetric sensors. Because of all this performances and implementation possibilities nanoparticles are nowadays extremely interesting field od research.