isogram guides https://isogram.design/guides/ Plain answers on 2D drafting and CAD. en AIA layer standards: how a name is built, the layers you need, and N, E, Dhttps://isogram.design/guides/aia-layer-standards/https://isogram.design/guides/aia-layer-standards/Sat, 07 Nov 2026 07:00:00 GMTHow an AIA (NCS) layer name is built from discipline, major group, minor group and status, the layers an architectural set needs, and -N, -E, -D. Drawing revision letters not used: which ones, why, and what comes after Zhttps://isogram.design/guides/drawing-revision-letters/https://isogram.design/guides/drawing-revision-letters/Fri, 06 Nov 2026 07:00:00 GMTWhich revision letters drawings skip and why, the full sequence from A to AA and beyond, and how to write a revision row above the title block. Dashed line not showing in AutoCAD layout: the fix, and why it happenshttps://isogram.design/guides/dashed-lines-print-solid/https://isogram.design/guides/dashed-lines-print-solid/Thu, 05 Nov 2026 07:00:00 GMTDashed line not showing in an AutoCAD layout? Set LTSCALE, PSLTSCALE and MSLTSCALE, run REGENALL, and see why dashes vanish at a viewport scale. ISO 5457 A3 border size: the frame, margins, marks and grid, size by sizehttps://isogram.design/guides/iso-5457-sheet-borders/https://isogram.design/guides/iso-5457-sheet-borders/Wed, 04 Nov 2026 07:00:00 GMTThe ISO 5457 A3 border: 20 mm filing margin, 10 mm on the other edges, centring marks, a 50 mm grid and where the title block sits, for A0 to A4. Scale 1:50 at A1 printed on A3: why it becomes 1:100https://isogram.design/guides/drawing-scale-on-a-smaller-sheet/https://isogram.design/guides/drawing-scale-on-a-smaller-sheet/Mon, 02 Nov 2026 07:00:00 GMTAn A1 drawing at 1:50 printed on A3 measures 1:100. The A-size arithmetic, a quick converter table, and why to write 1:50 @ A1 with a scale bar. ISO 7200 title block, field by field, on any sheet sizehttps://isogram.design/guides/iso-7200-title-block/https://isogram.design/guides/iso-7200-title-block/Sun, 01 Nov 2026 07:00:00 GMTThe ISO 7200 title block field by field: the nine mandatory fields, the optional ones, the 180 mm width limit and where it sits on A0 to A4 sheets. Text height for scale 1:100: the sum, the chart, and how to stop doing ithttps://isogram.design/guides/text-height-for-scale/https://isogram.design/guides/text-height-for-scale/Sat, 31 Oct 2026 07:00:00 GMTText height at 1:100 is the paper height times 100: 2.5 mm prints from 250 mm. A chart for every usual scale, and how to skip the sum entirely.