In CAD lettering and annotation for technical drawings, to maintain clarity and a consistent visual hierarchy you should limit the number of different fonts on a single sheet to how many?

Introduction / Context:
Readable lettering is essential for standards-compliant drawings. Excessive font variety reduces legibility, complicates revisions, and conflicts with company or ISO/ASME standards. This item focuses on best practice for font count.

Given Data / Assumptions:

• We consider a single drawing sheet produced in a CAD system.
• The goal is maximum clarity and professional consistency.
• Standard technical fonts (e.g., ISO 3098 or clear sans-serif CAD fonts) are assumed.

Concept / Approach:
Consistency is key. A single font type (with variations like height or weight for titles vs. notes) simplifies reading across notes, dimensions, and tables, and aligns with many drafting manuals recommending one lettering style per drawing.

Step-by-Step Solution:

Verification / Alternative check:
Review drawing standards: many in-house CAD standards specify a single approved font (or a single family) to ensure uniform output across departments and plotters.

Why Other Options Are Wrong:

• Two/Three: increases visual noise and inconsistency.
• Any number: unacceptable for engineering documentation quality control.

Common Pitfalls:
Using a decorative font for titles and another for dimensions; instead, vary text height or bolding within the same font to preserve clarity.

Final Answer:
One