ISO, US Architectural, Engineering, and Press Sheet Guidance For Print and Reprographics Workflows
This article provides context, explanations, and decision guidance for working across U.S. and international paper size standards commonly used in architecture, engineering, construction, and reprographics.
What This Reference Covers
This guide is designed for:
- Architects and engineers
- Reprographics and print teams
- Project managers coordinating mixed standards
- Anyone submitting, printing, or reviewing technical drawings or printed materials
You’ll find:
- ANSI, ARCH, and ISO size references
- Press sheet sizing (RA/SRA)
- Guidance on when to use each format
- Common pitfalls when converting between systems
This reference focuses on document, drawing, and press sheet standards. Common print products (such as business cards or postcards) are intentionally treated separately.
ANSI Series (U.S. Engineering & Office)
The ANSI paper size system is the primary standard used across engineering, technical documentation, and general office workflows in the United States.
Common ANSI sizes include:
- 8.5 × 11 (ANSI A): Letter
- 8.5 × 14: Legal
- 11 × 17 (ANSI B): Tabloid / Ledger
- 17 × 22 (ANSI C)
- 22 × 34 (ANSI D)
- 34 × 44 (ANSI E)
ANSI sizes are widely supported in printers, CAD software, and office applications. However, ANSI formats do not scale proportionally and are not interchangeable with ISO or ARCH sizes.
ARCH Series (U.S. Architectural)
The ARCH series is primarily used for architectural drawings and construction document sets in the United States.
Common uses include:
- 18 × 24 (ARCH C): review and study sets
- 24 × 36 (ARCH D): construction document sets
- 36 × 48 (ARCH E): large-format presentation drawings
Important:
ARCH sizes use a 3:2 aspect ratio and are optimized for architectural layouts. They are not interchangeable with ISO formats, even when dimensions appear similar.
ISO Paper Sizes (International Standards)
The ISO paper size system is the internationally adopted standard for document and drawing formats used across engineering, architecture, and technical disciplines. Defined by ISO 216, the system provides a consistent framework that allows documents to scale predictably across sizes.
Core principle:
ISO paper sizes follow a proportional scaling system that allows documents to be reduced or enlarged while preserving layout and relative scale.
Example:
- A0 → A1 → A2 → A3 → A4
- Each step halves or doubles the sheet while maintaining proportion
Important note:
ISO sizes are not interchangeable with U.S. ANSI or ARCH sizes, even when dimensions appear similar.
ISO A-Series (Finished Sizes)
The ISO A-series is the primary international standard for finished documents and technical drawings. It is widely used outside the United States and on global or multinational projects.
The A-series is typically used for:
- Technical drawings and construction documents
- Engineering and architectural plans
- Office documents, reports, and manuals
- General-purpose printing and copying
ISO B-Series (Posters & Books)
The ISO B-series is typically used for:
- Posters
- Large-format graphics
- Books and reference materials
These sizes are less common in AEC workflows but frequently appear in commercial and marketing print.
ISO C-Series (Envelopes)
The ISO C-series is designed specifically to hold A-series sheets without folding.
Examples include:
- C4 fits A4
- C3 fits A3
- C5 fits A5
ISO Press Sheet Sizes (RA & SRA)
What Are RA and SRA Sizes?
RA and SRA sizes are press sheet formats, not finished document sizes. They are intentionally larger than ISO A-sizes to allow room for:
- Bleed
- Trimming
- Press grippers (sheet hold-down on printing equipment)
Think of RA and SRA sizes as “A-size plus working margins.”
They should never be specified as finished drawing or document sizes.
RA-Series (Raw Format)
RA sheets provide additional margin beyond A-sizes and are commonly used for:
- Offset printing
- Digital press work
- Jobs with standard bleed requirements
Examples:
- RA1 trims to A1
- RA2 trims to A2
SRA-Series (Supplementary Raw Format)
SRA sheets are larger than RA sheets and provide extra room for:
- Heavier stocks
- Full-bleed designs
- Color-critical or tight-tolerance jobs
Use SRA sizes when additional production flexibility is required.
Choosing the Right Size
Use ANSI Sizes When:
- Working in U.S. engineering or office workflows
- Producing technical, mechanical, or infrastructure drawings
- Preparing consultant-driven documentation
Use ARCH Sizes When:
- Projects are U.S.-based and architect-led
- Producing construction document sets
- Coordinating with local jurisdictions
Use ISO Sizes When:
- Working on international or multi-country projects
- Submittals require ISO compliance
- Teams are standardizing around scalable formats
Use RA or SRA When:
- Printing full-bleed designs
- Running offset or digital press jobs
- Trimming is required after printing
- Using heavy or specialty stocks
Common Conversion Warnings
- A1 and 24 × 36 are similar but not the same
- 22 × 34 does not equal any ISO size
- Scaling is required when converting between ANSI, ARCH, and ISO
- Always confirm final print size before submission
Misunderstandings at this stage are one of the most common causes of rework and delays.
Metric ↔ Imperial Reference
- 1 in = 25.4 mm
- 1 mm = 0.039 in
- 1 ft = 12 in
- 1 ft = 304.8 mm
- 1 m = 39.37 in
Metric values rounded to the nearest millimeter unless otherwise noted.
Download
- Printable Print Size Quick Reference (PDF)
Need Help with Printing or Reprographics?
CorePrint Solutions supports:
- AEC reprographics
- Wide-format and large-format printing
- Press sheet production
- National print services and logistics
If you have questions about file setup, sizing, or production requirements, our team can help ensure your job is printed correctly the first time.