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What resolution should an A1 architecture board be?

For print, 300 dpi at full size: 7016 x 9933 pixels for a vertical A1. For a board read from a metre away or judged on screen, 150 dpi (3508 x 4967) is often enough. The brief always wins.

By the Sketchfest team9 min read

A printed vertical A1 board with a render of a riverside boathouse on a studio wall, with an architect out of focus beside it

Most competition boards now travel as files. Of the nine briefs we read in October 2026, eight wanted files only, just three named a dpi, and the upload limits ran from 1 MB to 25 MB a file. So the right resolution depends on three things: the size of the board, how far away people read it, and the file the brief will take.

The short answer

Printed and read up close: 300 dpi at full size. Read from a metre or more, or judged on screen: 150 dpi is often enough, a quarter of the pixels. When a brief or a printer names a number, use theirs.

Your boardAim forVertical A1 in pixels
The brief states pixels or dpiExactly what it saysAs stated
Printed and read up close, or the printer asks for 300 dpi300 dpi7016 x 9933
Printed and pinned up, read from a metre or more150 to 200 dpi3508 x 4967 to 4677 x 6622
Judged on screen only, or a small upload limit150 dpi, then compress3508 x 4967

Why distance changes the answer

A pixel twice as far away looks half as big. The poster printer Paperlust explains: "300 dpi began as the benchmark for documents read at arm's length." From twice that distance, 150 dpi looks about the same. Treat that as a rule of thumb: we found no standard that sets a resolution for boards. But "The same poster that is seen from across a room can also be inspected up close", the printer warns, and it asks for 300 dpi on every poster.

Pixels, ppi and dpi in plain words

Pixels per inch (ppi) is how many pixels sit in an inch of the printed board. Dots per inch (dpi) is how many ink dots a printer lays down: HP's architectural DesignJet printers reach up to 2400 x 1200 dpi. Briefs use "dpi" for both, meaning pixels per printed inch.

A dpi figure means nothing without a size: an A1 at 150 dpi has, within six pixels, the pixels of an A3 at 300 dpi. That is why the clearest briefs give both, as ASAI's Architecture in Perspective competition does: "300 dpi @ A5 paper size, or equivalent is recommended." And typing a new number into a resolution box changes nothing unless the pixels change too: in Photoshop's Image Size dialog, it is the Resample option that adds or removes pixels.

What counts on a board is each image's effective resolution: its pixels divided by the size it is placed at. A render 3,000 pixels wide, placed 25.4 cm (10 inches) wide, prints at 300 ppi. Stretched to 50.8 cm, it drops to 150 ppi. InDesign records both numbers for every placed image: Actual PPI, "the native resolution of a placed graphic", and Effective PPI, "the resolution of a graphic after it has been resized".

A0 to A3 in pixels

The A sizes are set by ISO 216. A0 has an area of one square metre, and each size below is the one above cut in half.

The sum: pixels = millimetres / 25.4 x dpi, rounded to the nearest whole pixel. There are exactly 25.4 mm in an inch. For the short side of A1 at 300 dpi: 594 / 25.4 x 300 = 7015.7, so 7016 pixels.

Size150 dpi200 dpi300 dpi
A0, 841 x 1189 mm4967 x 7022 (34.9 MP)6622 x 9362 (62.0 MP)9933 x 14043 (139.5 MP)
A1, 594 x 841 mm3508 x 4967 (17.4 MP)4677 x 6622 (31.0 MP)7016 x 9933 (69.7 MP)
A2, 420 x 594 mm2480 x 3508 (8.7 MP)3307 x 4677 (15.5 MP)4961 x 7016 (34.8 MP)
A3, 297 x 420 mm1754 x 2480 (4.3 MP)2339 x 3307 (7.7 MP)3508 x 4961 (17.4 MP)

Pixels are short side by long side; for a horizontal board, swap them. MP means megapixels.

  • Halving the dpi quarters the pixels.
  • The numbers grow fast. Uncompressed, in ordinary 8-bit RGB, an A1 at 300 dpi is about 209 MB of pixels, and at 150 dpi about 52 MB.
  • Briefs use the same sums. The RIBA President's Medals asked for the optional portfolio at 150 dpi and 1,754 x 2,480 pixels: A3 at 150 dpi, to the pixel.

How much of a board one image covers

At 300 dpi, a centimetre of board takes about 118 pixels; at 150 dpi, about 59.

Image widthAt 300 dpiAt 150 dpiAcross a vertical A1
1,024 pixels8.7 cm17.3 cm44 ppi
2,048 pixels17.3 cm34.7 cm88 ppi
4,096 pixels34.7 cm69.4 cm175 ppi
8,192 pixels69.4 cm138.7 cm350 ppi

For your own layout, start from the frame: a frame 400 mm wide needs 2362 pixels at 150 dpi and 4724 at 300 dpi.

What real briefs ask for

We read the submission rules of nine competitions and awards on 27 October 2026. No two ask for the same thing.

CompetitionBoardsFormatResolutionFile limit
RIBA President's Medals 2026, Bronze and SilverUp to 10, horizontal strongly recommendedJPG onlyAt least 300 dpi, or 7,000 x 4,500 pixelsNone stated at full size; a second web set at 1 MB each
Europan 18 (2025, the latest session)3 x A1, verticalPDFNot stated20 MB
ISA-iSUN Design Challenge 2026, supported by RIBA4 x A1, horizontalNot statedNot statedNot stated
AIA and ACSA COTE Top Ten for Students 2027Up to 2, 24 x 36 inBMP, GIF, JPEG or PNGNot stated20 MB each
ACSA and AISC Steel Competition 20274, 20 x 20 inBMP, GIF, JPEG or PNG, "high resolution"Not statedNot stated
ETSAG Granada student competition 2026Up to 2 x A1, vertical, on rigid boardPrints, plus a PDF copyNot statedNot stated
ASAI Architecture in Perspective 40 (2026)Up to 10 imagesJPG or PNG300 dpi at A5 or equivalent4 MB
RIBA Journal Eye Line 2026Up to 3 imagesNot stated300 dpi25 MB
The Architecture Drawing Prize 20261 imageNot statedNot statedNot stated
  • Only three of the nine name a dpi. Where a brief gives no dpi, work from the tables above and the file limit.
  • Some rules leave a gap. Europan's 20 MB limit doesn't say whether it is per panel or for all three. Ask the organiser well before the deadline.

On AI images and anonymity, see can you use AI renders in architecture competitions.

Colour, format and file size

RGB or CMYK. Screens mix light (RGB), printers mix ink (CMYK). In Paperlust's words, "vivid neons, saturated reds, and bright blues often look duller on paper than on screen." For a board judged on screen, export in sRGB with the profile embedded: the W3C's colour specification says untagged images must be treated as sRGB. For print, ask the printer. HP's guide says to convert to CMYK before printing; the Melbourne School of Design print room recommends Adobe RGB (1998) for the document and CMYK for JPEG and TIFF exports, and shows how to preview the result with Proof Setup and Proof Colours.

FormatText and drawingsColour
PDFLive text and vector lines stay sharpRGB or CMYK
JPEGPixels; strong compression blurs themRGB or CMYK
PNGPixels, kept exactlyRGB, no CMYK

JPEG is lossy by design: heavy compression shows first on small text and thin lines. PNG is, in the W3C standard's words, for the "lossless, portable, well-compressed storage" of images, but the Melbourne print room advises against it for print because it carries no CMYK data. Paperlust calls PDF "the most reliable format for commercial printing".

To get under an upload limit:

  1. Pick the dpi from the limit: 300 dpi for 20 MB or more, 150 dpi for a few megabytes.
  2. Lower JPEG quality in steps, checking the smallest text at 100%.
  3. In a PDF, compress the images, not the text. InDesign's PDF export can downsample images and keep text live.
  4. Rasterise heavy hatches, as the Melbourne print room suggests.
  5. Cut pixels before quality: 150 dpi at good quality beats 300 dpi at very low quality.

Text, lines and small images

A point of type is 1/72 of an inch, about 0.35 mm. None of the nine briefs set a minimum text size. At 150 dpi a point gets about two pixels, at 300 dpi about four, so small text in a JPEG blurs first. Likewise, at 150 dpi a pixel is 0.17 mm wide, so a 0.1 mm line is thinner than a pixel and can turn grey or break up; at 300 dpi it gets about 1.2 pixels.

Enlarging adds pixels, not detail. As Paperlust puts it, "Upscaling a bad source rarely produces a good print." Adobe Camera Raw's Super Resolution makes an image with "2x the width and 2x the height of the original image or 4x the total pixel count", and can be applied only once.

Make the render for the board

In the Chaos and Architizer survey published in 2025, 43% of firms called slow rendering times a major challenge. ChatGPT can start from an image you upload and the changes you describe, which suits mood. On a board, though, the render has to show your design as you drew it.

Sketchfest is built for that job. Upload a hand sketch, a CAD screenshot or a 3D view, and you get a photoreal render of your design in seconds. It follows your drawing, there are no prompts to write, and it works in your browser.

RenderHand sketch
RenderHand sketch
A hand sketch of a curved pavilion on a grassy hill and its render, made with AI in Sketchfest. Drag the line to compare.

To get a drawing ready, see how to turn a sketch into a realistic render; for the wider choice of tools, how to render architecture with AI.

Quick answers

What is A1 size in pixels?

At 300 dpi, 7016 x 9933 pixels, about 70 megapixels. At 150 dpi, 3508 x 4967. For a horizontal board, swap the numbers.

Is 72 dpi enough for an A1 board?

At 72 dpi an A1 is 1684 x 2384 pixels: fine for a web preview, but well below the 150 dpi rule of thumb.

Sources

  1. ISO, ISO 216:2007 Writing paper and certain classes of printed matter, Trimmed sizes, A and B series (second edition, 2007; last reviewed and confirmed in 2021; checked 27 October 2026)
  2. ISO 216:2007, sample pages with Table 1, via iTeh Standards (A0 has an area of 1 square metre; A0 to A10 in millimetres; checked 27 October 2026)
  3. NIST, Guide to the SI, Appendix B.8: Factors for units listed alphabetically (inch = 0.0254 m exactly; computer point = 1/72 inch; updated 18 August 2025)
  4. RIBA President's Medals 2026, Entry Nomination Form (Bronze and Silver boards and portfolio; deadline 27 July 2026; checked 27 October 2026)
  5. Europan 18, Rules (2025 session, A1 panels; checked 27 October 2026)
  6. ACSA, 2027 COTE Top Ten for Students, Program (with AIA; submissions due 2 June 2027; checked 27 October 2026)
  7. ACSA, 2027 Steel Competition, Program (with AISC; submissions due 2 June 2027; checked 27 October 2026)
  8. ISA-iSUN Design Challenge, Guidelines and RIBA, ISA-iSUN Design Challenge for Small Island Developing States (phase 1 closes 15 November 2026; checked 27 October 2026)
  9. ETSAG, Universidad de Granada, Bases del concurso (in Spanish, March 2026; deadline 15 May 2026; checked 27 October 2026)
  10. ASAI, Terms and conditions for the Architecture in Perspective competitions (Architecture in Perspective 40; revised 24 February 2026)
  11. RIBA Journal, Eye Line 2026: enter now (published 2 March 2026; entries closed 11 May 2026)
  12. Make Architects, Entries open for the Architecture Drawing Prize 2026 (1 June 2026) and World Architecture Festival, The Architecture Drawing Prize (checked 27 October 2026)
  13. Paperlust, Poster Size in Pixels: What Resolution You Actually Need (Anna Devanti, 8 August 2026, updated 22 October 2026; a print shop's own guidance)
  14. HP, Architectural board printing: best practices for professional results (25 September 2025; a printer maker's guide)
  15. Melbourne School of Design print room, Adobe PDF preparation guide and Managing colours (University of Melbourne; checked 27 October 2026)
  16. Adobe Help, Resample option in the Image Size dialog (Photoshop; updated 17 March 2026)
  17. Adobe Help, Enhance images in Camera Raw (Super Resolution; updated 14 October 2024)
  18. Adobe Help, Links panel in InDesign and Adobe PDF export options (both updated 2 June 2026), with the InDesign 2026 object model reference, Image (actualPpi and effectivePpi; version 21.5.1.73; an independent copy of Adobe's scripting reference)
  19. W3C, CSS Color Module Level 4 (untagged images treated as sRGB; Candidate Recommendation Draft, 26 October 2026)
  20. W3C, Portable Network Graphics (PNG) Specification, Third Edition (W3C Recommendation, 24 June 2025)
  21. JPEG committee, JPEG 1 (ISO/IEC 10918-1 and ITU-T T.81, a lossy format; checked 27 October 2026)
  22. Chaos and Architizer, 2025 State of Architectural Visualization (1,000+ respondents, November 2024; run by a software maker)
  23. OpenAI Help, Images in ChatGPT (upload an image and describe changes; checked 27 October 2026)

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