Using raster (PNG) format files with Big Blue Saw
Our computers try to use the drawing you upload to determine what your part will look like. But they can only do that if the file is formatted correctly. Here are some tips to help you become successful with Big Blue Saw.
Understand what kinds of parts can be made with Big Blue Saw
All of Big Blue Saw's parts are made with an abrasive waterjet. This means that two dimensional designs are cut from flat sheets of material. Read the FAQ What kinds of parts can I make with Big Blue Saw? or all the FAQs on parts for more information.
Limitations of raster format (PNG) files
Parts created from files in the PNG format are not going to be as accurate as parts designed using CAD tools and the DXF format. Curved areas will not be perfectly smooth, and corners will not be perfectly sharp. Diagonal lines might not be perfectly straight. Using PNG files also makes it very difficult to obtain perfect sizing and spacing between features on your part. In general, we only recommend making parts from PNG files when accuracy is not important, such as for decorative pieces.
Tips for creating raster format files for use with Big Blue Saw
- Use a white background.
- Use black to draw your part. This provides the highest contrast with the white background.
- Fill in any areas with black where you want the material to be in the final part. Areas in white will be cut away. Don't use black to create an outline of the part.
- Don't use antialiasing. Antialiasing is a technique used to make lines and edges appear smoother when rendered on your computer screen. Big Blue Sawï¿½s software can detect the edges of your part automatically and is only confused by antialiasing.
- Don't use alpha transparency. The PNG format supports making images transparent so that a background can show through them. Make sure that this feature is turned off in your image editing software. You donï¿½t need a transparent background; just fill in the background with white.
- Include only one part per drawing. Put only one part in each file you upload.
- Use a fairly high resolution file. You should aim for about 100 pixels per inch of completed part. If your part is 6 inches by 4 inches, a resolution of 600x400 pixels should produce good results.
The image on the left will result in a heart shaped part at the end of the process. The image on the right will result in a very thin outline of a part: all the white area will be cut out from the center, leaving you with only the outline. This is probably not what you want.
The circle at the top left is antialiased, which looks smoother than the non antialiased circle on the bottom left. But when zoomed in, the border of the antialiased image is much fuzzier, making it harder to find the edge.
The file shown on the left is correct; a small tab is used to join pieces together. The file shown on the right is incorrect, as it includes more than one part in a single file.