Invented by Adobe systems in 1993, the portable document format
(PDF) is a data format for documents, which can be used on many
different platforms. In the last few years the PDF format has had
unrivaled success, and is not only for text documents but can also
be implemented for blueprints from CAD software. The ground
breaking idea behind the success is the scalability of the
document. The scalability of PDF is possible because PDF is vector
based and not pixel based.
This allows you to enlarge a blueprint and still keep the original
clarity of the drawing when printing. The layer technology allows
one to print or omit any layers or groups of layers you want. The
native PDF text format allows you to search a document with
keywords. In short, PDF is incredible for the use of CAD.
Unfortunately the possibilities of the PDF exchange are often not
used. A lot of files that are called “PDF“ are really
not a true “PDF“ format, they are only a relater picture
with a PDF frame.
1. Vector Based PDF Made from CAD Systems
Vector based PDF files are the real PDF data format. The native PDF
entities such as native polylines, native texts, and native hatches
are used. This kind of PDF files are created directly from a CAD
application without using a plotter interface. This kind of PDF is
excellent for converting the data into DXF and DWG. The coordinates
are exact enough to be used for the purpose of CAD.
2. Vector Based, Through a Plot Interface Exported PDF
File This type of PDF data is exported from a CAD
application through a plot interface. This type of PDF data has
only lines and hatches, often with a resolution of 75 dpi. The
principle of scalable data, because of the inaccuracy of the
coordinates, is really degraded.
This kind of PDF is expectable for converting the data into DXF and
DWG. The coordinates are of bad quality but are enough to be used
for the purpose of CAD.
3. PDF File with Raster Pictures This type
of PDF data doesn‘t include any native PDF elements like
lines, hatches or text. This can only be converted with a fair
amount of quality. This kind of PDF contains only raster pictures.
These raster pictures have to be vectorized during a conversion to
DWG or DXF. This kind of PDF is not expectable for converting the
data into DXF and DWG. The coordinates are of very bad quality and
are not enough to be used for the purpose of CAD.
4. Hybrid (Vector and Raster Based) PDF
Files This is a combination of vector and raster
formats, with all the pros and cons in one. The hybrid PDF is the
real PDF file that contains the lines, texts and hatches within.
This data also contains raster pictures. In this case using the
program Print2CAD you have to decide how you handle the PDF raster
pictures. Print2CAD offers you a lot of possibilities to vectorized
raster pictures. This kind of PDF is very expectable for converting
the data into DXF and DWG. The coordinates are of good quality and
are enough to be used for the purpose of CAD.
