raster or vector

[Frank barry]

Hi again just another question

What is meant when you say raster engrave or vector engrave and when would you use each of them

thanks in advance

[Cindy Rhoades]

Vector is cutting and the raster is engraving the image

[Glen Monaghan]

Raster engrave (or simply rastering) is the "normal" engraving where you are making a mark on/into the substrate but not (normally) cutting through. It's done in a raster or back-and-forth, line-by-line fashion similar to the way a dot matrix printer works.

Vectoring is when the laser beam goes directly from point to point, similar to the way a plotter works or the way you would draw on a piece of paper. Most often, this is the mode used to cut through the substrate, but sometimes it's also used to engrave a mark on/into the substrate without cutting all the way through. Since vectoring is typically used for cutting and rastering is the normal method used to engrave without cutting through, people normally say "vector engraving" to differentiate from cutting or raster engraving.

Vector engraving is pretty much only used for outline text and line drawing types of pictures since you can't change the stroke/beam width. It can be much faster than rastering with such images, especially when the line drawings are large. For example, consider engraving a 12" square box made of hairline thin lines. If raster engraved at 300 dpi, the beam would have to sweep the full 12" width (plus some extra for acceleration/deceleration at the start and end of each sweep) 300*12 times for a total of 300*12*12 inches (plus a bit extra for the acc/dec distances). In contrast, if vector engraved, the beam would only have to travel around the perimeter for a total of 4*12 inches. That's almost a 1000 times less beam movement compared with rastering in this example. Not to say nearly 1000 times faster though, since many machines will skip over the nearly 12" of blank space in the center of the square at highest slew speeds when rastering rather than the specified raster speed. Still, the vectoring would be significantly faster in this case.

[Dee Gallo]

Welcome to the Creek, Frank! Glen has given you a great description, so read it twice and you'll be okay.

Keep in mind also that photographs and all bitmapped images will raster only, as there are no outlines to vector either cut or engrave. So you have two kinds of images, bitmap and vector. Then you have two ways to laser, raster (engrave) and vector (cut). The word vector is used in both but mean different things... although both refer to lines moving from point to point. Vector engraving is basically just cutting part way through the substrate controlled by your settings. Only hairline will vector, by the way. Thicker lines over .5 point will engrave.

cheers, dee

[Frank barry]

thank you all for your coments


I have learnt so much from this forum