Although I see less and less use of the .plt file for import I still occasionally get questions on using the .plt or plotter. One of the common issues when importing or exporting a plt file is that the curves will break down and not be smooth. This can be easily resolved by increasing the curve resolution in the export filter. Note this same issue was prevalent when I used to get files from AutoCad where the 0’s are more a hexagon shape
Here is what I mean
Here is an “R” that was imported from a .plt file. You can see that the resolution on the curve is rather poor.
Here is an R and D Created in CorelDraw
To test this I have created an “R” and a “D” in CorelDraw.
Export the File
To export the file go to FILE (1) | EXPORT (2)
Select your .PLT Extension
Type in a name (1) and select the HPGL Plotter File format (2). Note: make sure you note the directory you are exporting to so that you can easily find the file.
Select the Advanced Tab
Once you click OK on the Export command window you will be taken to another window – pictured above. The change we need to make is found under the “Advanced Tab” (1)
Type in 0.001
I want my curve resolution to be as low as it can be so 0.001 or even 0 is fine (1). Click on OK (2). The default of .02 is not good enough.
Two Images Compared
You can see that the imported image is almost as good as the original and certainly better than our first image than had the default values applied
The original image is at the top and the imported image is at the bottom. With the nodes activated you can see that the imported image has more nodes than the original image. Remember each node is a direction change and thus the least amount we have the better it is – as long as we do not sacrifice the quality of the image.
EPS Versus Original
How about if I use a different file format such as EPS. You can see that the difference in the two formats (the original is on top) is the negligible
EPS Versus Original
When I look at the nodes you can see that the difference is basically nothing. So if you are looking at exporting or importing vector files I suggest that you use EPS as a better format or better yet PDF.