Often, when our customers submit art for printing, we find that they have no idea what a Vector file is. Most individuals that are not professional graphic designers do not have a clue what Vector art is (and why should they) and most companies do not have graphic designers on staff. There are even some people working as graphic designers, who do not know what a vector file is. (OK, now that is sad.)
Hopefully we can eliminate some of the confusion and answer the question… What is Vector Art. We will describe, as best we can, what vector art is, and how you can recognize it.
Vector art is one of the two forms of art used by computers, the other form being bitmap art (raster). Bitmap art is identified with file names ending in .gif, .bmp, .jpeg, .jpg, .png, and .pcx. Vector art files are typically saved as .eps, .ai, or .cdr files. Vector art is mathematical algorithms created using software programs, such as Adobe Illustrator, Freehand, Corel Draw, Quark and a few others. These programs use mathematic equations and geometric primitives (points, lines, and shapes) to create art that is clean, camera ready, and can be scaled infinitely, without losing any quality or clarity. The same art may be used for a business card, to a poster, to a billboard.
A bitmap file (raster), is a dot matrix data structure it uses pixels (small dots or squares of color) to create an overall image. Rather it is called Raster images or bitmap files they are the same thing.
A bitmap is technically characterized by the width and height of the image in pixels and by the number of bits per pixel (a color depth, which determines the number of colors it can represent).
The Raster art file has rough, pixilated edges. The art becomes distorted when the picture is enlarged. Every time you edit the file it loses some of it’s clarity.
Raster Graphics, such as photographs, and graphics files created in Adobe Photoshop, Paint Shop Pro, and other Raster programs, can be used for some screen printing applications or digital printing. In most cases, especially with art such as logos and numerous colors printers need Vector art to achieve the quality print that you want and expect.
1. Can I convert a.BMP,.GIF or.JPG to vector?
Unfortunately no. A bitmap file is created differently and just like putting another cover on a book, you still have the same pages inside.
2. I converted a Photoshop file to.EPS, why can’t I use this as vector art?
Vector art images use lines to create images, photographs can’t normally be turned into a vector image. A bitmap or raster file uses dots, they are not created in the same manner. In a vector file everything is a separate item. If you have an apple with a worm in it you can change the apple to green at anytime and the worm can become a tiger if you so choose without altering or affecting the other object. Vector art must have been created as a vector file. You cannot take a raster file created in Photoshop (for example) and save it with an.eps,.ai., or.cdr extension and have it magically become a vector file. Once a bitmap always a bitmap unless recreated or traced.
How do you tell if a file is a vector art file?
You can usually identify vector art by process of elimination. If it has the wrong extension, it is definitely not vector. I encourage customers if they are not sure enlarge the image to 400 or 800% and if the edges are extremely rough and pixilated it is probably NOT a vector image. If you still can’t tell send it to your printer and they can let you know. A.pdf file may be vector or raster. It depends on how it was originally created.
I’m going to get a little technical here, hopefully not too much! The difference between these types of art files lies in how an image is stored within the art files themselves. Bitmap files consist of a series of numbers and colors that represent coordinates within the image area’s grid. To store a bitmap image, the computer creates a gridwork of the image area. (Pixels are the tiny dots. Remember dot matrix printers.) That’s all there is to a bitmap file. A series of numbers representing pixels and their colors.
Vector files are nothing like a bitmap file. A vector file contains the information for creating lines. It contains a starting point and an ending point for each line. With those coordinates, it also stores a vector equation for each coordinate. A vector equation indicates both direction and velocity. Using these coordinates and vectors, the computer can draw a line from point A to point B with any proper curve automatically created. Vector files sound really technical and complex in their creation.
Vector images have a number of advantages over bitmap images, including:
If you try to enlarge a bitmap image, your computer can only enlarge the size of the squares making up the image area. You still have squares; that is why bitmap images get jagged as you enlarge them. Vector images remain smooth because your computer merely re-computes the coordinates of the points and adjusts the vector equation constants, never sacrificing quality.
Each set of lines in a vector image represent separate and distinct objects. Every object can be re-edited at any time. For example, let’s say you created a vector art file with a circle in the background. You could open the vector file at any time and change the circle to a square, oval, apple, etc. Each object is a separate item within a vector file.
Keep in mind that if a professional graphic designer created your art/logo for you, they should have saved your artwork as vector art file, even if they did not send that file to you. Some designers do not provide their clients with vector art, because most clients will not be able to open the file. If you had a professional logo designed for you, but all you have is a.JPEG, or a similar file, contact your artist, and ask them for the vector art file. Bear in mind, unless you have specific software to open the file you cannot open it; but you can send it on to the printer and they should be able to open it.
Note of caution, in the last few years I’ve seen professional graphic designers create logos in Photoshop. A Photoshop file is bitmap (raster) and will not usually work if you need a logo for printing or promotional items. This IS NOT a vector file. So check carefully with your designer before you have them begin designing your logo or art for you.