Drawing Authoring Guide

During automated drawing extraction, our Optical Character Recognition (OCR) system reads the PDF drawing files and automatically extracts sheet numbers and any attributes defined in title block templates for review.

This topic provides best practice for designers who are working in AutoCAD or other authoring software. By adhering to these basic principles and best practices when generating drawings, you can increase the accuracy of OCR's ability to read attributes and attribute values.

Note: See How to Format Callouts for Automatic Hyperlinking for details on the correct way to design sheet number callouts and text in drawings.

Sheet Number Format and Location for Non-Capture Areas
Sheet Number Labeling
Custom Attribute Value Format
PDF Drawing Settings
- Vector v Raster
- DPI settings

Sheet Number Format and Location for Non-Capture Areas

The following guidelines are for formatting sheets numbers when a template isn't selected in the extraction process. Automatic OCR occurs when the system will attempt to read the sheet number from the title block.


Location	In the title block at the bottom right corner of a landscape format drawing.
Text orientation	Horizontal text which reads from left to right.
Font size	Larger font size compared to the surrounding text.
Font type	Standard or common font with continuous, filled-in bold characters. There should be white space between each character. Avoid italics, stencils, or fonts which look like handwriting. Try not to write or draw anything on top of (or right next to) the sheet number. Ideal example of a sheet number in a title block:

Sheet Number Labeling

OCR expects sheet numbers to start with an alphabetical character. Sheet numbers which start with a number that looks like an alphabetical character may be extracted as an alphabetical character. For example, zero 0 may be extracted as oh O, or one 1 may be extracted as the letter l. Sheet numbers can be edited during the Review and Edit Attributes step of the extraction process, and after saving.

Important: Do not use underscores or spaces in the sheet number as they may be removed by OCR. Use hyphens or periods instead.

Custom Attribute Value Format

The most important settings for custom attribute extraction are the orientation and language set on the capture area in the title block. Vertical or non-English text values will not be read correctly if the options are not set correctly. This is relevant for drawing capture areas, either in templates or during extraction.

Revision number: Add the current revision number directly in the title block in a manual area drawing, either in templates or on the fly. Addition to the revision block. This means you can always extract the latest revision information.

See Add and Capture Title Block Attributes for more details on how to add attributes, draw capture areas, and check the orientation and language settings.

PDF Drawing Settings

Vector v Raster

Drawings should be generated from their original design software to a PDF vector format for optimal OCR readability.

DPI settings

When exporting drawings from your design software to PDF, select an appropriate image quality of 150 DPI or higher, without significant compression artifacts.