Major role of CAD in printing industry

Computer Aided Design (CAD) simply means designs created by the use of computers in the engineering or technical field. CAD has impacted the design process as IT has influenced every industry and its operation methods. The greatest blessing is CAD enables the creation of designs without any need for building a dummy thus reducing cost and time factors.

CAD is widely used by architects for creating extensive views of buildings and other structural designs. The growing fashion industry also uses CAD for textile designing, fabric coloration and other fashion materials. CAD has software for plant designing by engineers. There are also power systems CAD for creating power systems where the designers can check for the effectiveness of their safety aspects. The future of CAD is promising as it leads to huge cost-benefit ratio.

CAD drawings are printed generally using a printer or a plotter. The process of printing is quite easy as you select the print or plot function from the menu. This selection sends data from the computer to a printer or plotter, which produces the final drawing. The drawings are absolutely tidy and depending on the quality of the printer, it is also sharp and accurate.

You can plot a drawing to any size by using an appropriate scale factor. You can choose the line thickness and colors for different drawing objects. You can also make other adjustments like rotating a plot, printing only certain predetermined areas of a drawing, or using select fonts for text and dimensions.

When working manually on a drawing board, you use a specific scale to draw diagrams. When you need to draw a small machine part, you draw it many times larger than its actual size. CADD uses the same principle to scale the drawings but in a different way. All CADD drawings are created on a full scale (1:1). Even if you have to draw the map of a township, you will draw it using 1:1 scale. You can draw to any size on the screen as you like and adjust the image using view-display functions. The actual scale of the drawing is determined when the drawings are plotted. The ratio between the plotting units and drawing units is called "scale factor".

The scale factor determines how big or small the drawing will be printed. It is important to know that once the plotting scale and sheet size are determined, you can draw an outline border indicating the maximum drawing area. The border reminds you that this is the maximum size diagram you can draw on that particular sheet. All drawing must necessarily be confined within this border or else they will fall outside the plotting area. You can arrange diagrams on a sheet and apply different scales to each diagram. Different programs use different protocols to accomplish this task. One protocol used is a special mode of working called page layout or paper space. Another protocol used involves specifying the plotting scale when you start a drawing.

There are two distinct varieties of printing machines called plotters and printers. Both are used to print CAD drawings. Diagrams are generally printed at about 300-600 dpi (dots per inch) accuracy, which is acknowledged by many as high precision for engineering drawings. For special graphic applications however there are machines that can print at 1200 dpi or higher accuracy.

Although plotters and printers essentially do the same job, there are differences the way they work. Plotters print drawings by plotting vectors. They print drawing objects one by one, just as we draw them on the screen whereas printers print data in a raster format and the drawing is printed line by line from top to bottom.

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