paper folding techniques

The main starting point for such technical designs is the crease pattern(often abbreviated as CP), which is essentially the layout of the creases required to form the final model. Although not intended as a substitute for diagrams, folding from crease patterns is starting to gain in popularity, partly because of the challenge of being able to 'crack' the pattern, and also partly because the crease pattern is often the only resource available to fold a given model, should the designer choose not to produce diagrams. Still, there are many cases in which designers wish to sequence the steps of their models but lack the means to design clear diagrams. Such origamists occasionally resort to the sequenced crease pattern (SCP) which is a set of crease patterns showing the creases up to each respective fold. The SCP eliminates the need for diagramming programs or artistic ability while maintaining the step-by-step process for other folders to see. Another name for the sequenced crease pattern is the progressive crease pattern (PCP).
Paradoxically enough, when origami designers come up with a crease pattern for a new design, the majority of the smaller creases are relatively unimportant and added only towards the completion of the crease pattern. What is more important is the allocation of regions of the paper and how these are mapped to the structure of the object being designed. For a specific class of origami bases known as 'uniaxial bases', the pattern of allocations is referred to as the 'circle-packing'. Using optimization algorithms, a circle-packing figure can be computed for any uniaxial base of arbitrary complexity. Once this figure is computed, the creases which are then used to obtain the base structure can be added. This is not a unique mathematical process, hence it is possible for two designs to have the same circle-packing, and yet different crease pattern structures.
As a circle encloses the maximum amount of area for a given perimeter, circle packing allows for maximum efficiency in terms of paper usage. However, other polygonal shapes can be used to solve the packing problem as well. The use of polygonal shapes other than circles is often motivated by the desire to find easily locatable creases (such as multiples of 22.5 degrees) and hence an easier folding sequence as well. One popular offshoot of the circle packing method is box-pleating, where squares are used instead of circles. As a result, the crease pattern that arises from this method contains only 45 and 90 degree angles, which makes for easier folding.

paper mache

Papier-mâché paste is the substance that holds the paper together. The traditional method of making papier-mâché paste is to use a mixture of water and flour or other starch, mixed to the consistency of heavy cream. While any adhesive can be used if thinned to a similar texture, such as polyvinyl acetate  (PVA) based glues (wood glue or, in the United States, white Elmer's glue), the flour and water mixture is the most economical. Adding oil of cloves or other additives to the mixture reduces the chances of the product developing mold.

 The paper is cut or torn into strips, and soaked in the paste until saturated
. The saturated pieces are then placed onto the surface and allowed to dry slowly; drying in an oven can cause warping or other dimensional changes during the drying process.
The strips may be placed on an armature, or skeleton, often of wire mesh over a structural frame, or they can be placed on an object to create a cast.
 Oil or grease can be used as a release agent if needed.
Once dried, the resulting material can be cut, sanded and/or painted, and waterproofed by painting with a suitable water repelling paint.
Before painting any product of papier-mâché the glue must be fully dried, otherwise mold will form and the product will rot from the inside out.

importance of paper bags+ fun

Now a days people had started taking interest in favor of Nature, now the people are making other also aware of global warming and all, they stared taking initiative to make their environment clean. Now people had under stand that how much hazard is this  but still some people are not serious about this they think that will be no loss if only they are using or they use one or two poly bags but they are not aware that even one poly bags is also not degradable for years and years and can led to death of any street animal. Very good alternative of this poly bags is now emerged in our society and that is “Paper Bags” these paper bags are only useful in all the way, they do not have any type of disadvantage in it. Paper bags have much importance the main important thing is that they are bio-degradable and if they are burn they do not pollute air as much as poly bags do.
If they are even eaten by any street animals then paper bags are digested by them and cause no harm to them.
Another crucial thing is about these bags are they are easily renewable as compare to other bags paper bags they can be given any shape , size and color easily.
The production of paper bags by they company or factory are also very easy for them they raw material require for making these paper bags are very cheep and easily available.
Many small scale industry or there are many home based factory who produce paper bags for the commercial purpose we use in our daily life used in carrying any small amount of product all though they are not of very good quality but they are used for general purpose. So paper bags also provide livelihood to other. So use of paper bags can be beneficial for all the living beings.