A skill that makes Claude design a poster the way a senior graphic designer does, then hand back the finished file. It builds the layout in Python in Claude's code sandbox, so every position, size and colour is a number it can state and check. You get a print PDF at the real size with bleed and the trim recorded for the printer, or a PNG at the exact pixels Instagram or Pinterest wants. It works from your brief, your copy and your brand colours, and it sizes the type from how far away people stand when they first see the poster.
It works in six stages and stops after each one for your decision: the brief, two written design directions, three thumbnails on the real grid, the full build, measured checks with one refining pass, then the hand-off and other sizes. Five reference files back it: print and screen sizes with dated sources, a guide to composition, type and colour, a tested Python layout kit, the build and check steps, and a worked example for a fictional record shop. It never invents copy, dates or prices, checks every date against its weekday, and rebuilds each extra format for its own shape instead of stretching one.
Switch on code execution first, or it can only write a spec for you to build by hand. Upload your font files; without them it uses a free open-licence font from Google Fonts as a labelled stand-in, and fetching one needs network access in the sandbox. It cannot take or generate photographs, so pictures come from you or are drawn as shapes. The PDF carries your CMYK values but no colour profile, so ask your printer for a proof. It sets Latin text only. Paste the copy word for word, name the viewing distance and attach the printer's spec sheet to skip most questions.
Claude skill · version 1.0
Poster designer
Checking your access.
In the download · 9 files
- SKILL.mdThe method Claude follows: brief, two design directions, three thumbnails, the full build, measured checks and a refining pass, then hand-off and other sizes, one stage at a time.
- README.mdHow to install it in claude.ai or Claude Code, how to start, and the licence.
- references/sizes-and-specs.mdPrint sizes in points and pixels, resolution, bleed and safe zones, type size by viewing distance, screen formats, WCAG 2.2 contrast, print colour, font licences and the code sandbox, each with its source and the date checked.
- references/worked-example.mdAll six stages for a fictional record shop's listening-night poster, at 18 x 24 in and as a feed post, with every number from a real run of the kit.
- references/composition-and-type.mdHow to write a design philosophy and its concept thread, two directions that really differ, the grid arithmetic, eight thumbnail structures, type and colour rules, and the refining pass.
- references/poster-kit.mdA tested Python layout kit that reads real font metrics and kerning, writes a vector PDF with bleed and a trim box, renders previews and runs the checks.
Install it and begin
01Install it in Claude CodeTerminal mkdir -p ~/.claude/skillsunzip ~/Downloads/poster-designer.zip -d ~/.claude/skills/# Start it with /poster-designer. If this is your first skill, type /reload-skills once.On claude.ai there is nothing to unzip: upload the zip as it is. Every step is on Install and use a Claude skill.
02Your first message to ClaudeText Use the poster designer skill. Design a [SIZE, FOR EXAMPLE 18 X 24 IN OR 1080 X 1350 PX] poster for [WHAT IT IS FOR]. It will be seen [WHERE IT HANGS AND FROM HOW FAR]. Our brand colours are [HEX CODES]. Here is the copy, word for word: [PASTE YOUR COPY]. Start with the brief.Attach your logo, any font files and photos at full size, and your printer's spec sheet if you have one. Switch on code execution first so Claude can make the files.
Try this
Your first poster with it
Take a real event or sale you have coming up and run the skill as far as the three thumbnails in one sitting. Pick one, let it build and check the full poster, then ask for one other size and lay the two files side by side.
Time: About an hour. You need: The copy, word for word, with every date and time, your brand colours as hex codes, plus CMYK if it will be printed, your logo as SVG or PDF, and your font files if you have them, the size, and where the poster will hang or show.
Look for
- A brief that names the viewing distance and sorts your copy into four levels.
- Two directions that differ in what leads the page, not only in colour.
- Type sizes worked out from the distance, with the sums shown.
- A contrast figure for every text and ground pair, with failing colours kept off small text.
- A question about a missing date or price, never a made-up one.
- A second size rebuilt on its own grid, not the first one stretched.
What to do it with
- ClaudeFree tier, paid above it
A language model that writes, edits, reads long documents and runs tools, including agents that work inside a codebase.
Bad at It is agreeable by default, so it will improve a bad idea instead of telling you it is bad. Ask it to argue against you and the quality of the answer changes.
- Claude CodeSubscription
An agent that reads a whole repository, edits files, runs the tests and explains what it changed.
Bad at It is fast enough to make a large mistake quickly. Work on a branch, read the diff, and never let it push. Watch the starting mode: on Pro, Max and Team plans it opens in auto mode, which Anthropic's own list says may read a .env file and send the key in it to the API that key belongs to. Switch it off.
- Google FontsFree
Open-licensed typefaces, hosted and self-hostable, covering many scripts.
Bad at Quality is uneven across the catalogue, and the defaults are the most-used type on earth.
Why it matters
Ask a chat for a poster and you get a picture of one, with invented details, type sized by eye, words crowding the trim and a file no printer will take. This skill makes Claude settle the copy and the viewing distance first, compose on a measured grid, check contrast, safe zones and every date with code, and refine by removing instead of adding. What comes back is a file you can send to print or post as it is.
- Type
- technique
- Period
- ongoing