--- title: Imprint: Signed, Expiring Image Rendering with Dynamic... description: Imprint is a Ruby gem that provides signed, time-limited image rendering with dynamic watermarks. It uses HMAC-signed tokens with expiration timestamps to... canonical: https://daily.dev/posts/imprint-signed-expiring-image-rendering-with-dynamic-watermarks-in-ruby-k6k43efrq twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Imprint: Signed, Expiring Image Rendering with Dynamic Watermarks in Ruby | daily.dev og:description: Imprint is a Ruby gem that provides signed, time-limited image rendering with dynamic watermarks. It uses HMAC-signed tokens with expiration timestamps to... og:url: https://daily.dev/posts/imprint-signed-expiring-image-rendering-with-dynamic-watermarks-in-ruby-k6k43efrq og:image: https://api.daily.dev/og/posts/k6K43efRQ.png og:image:alt: Imprint: Signed, Expiring Image Rendering with Dynamic Watermarks in Ruby og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Imprint: Signed, Expiring Image Rendering with Dynamic Watermarks in Ruby **[Ruby Flow](https://daily.dev/sources/rubyflow)** · 4 min read · 1 upvotes · 0 comments ## Summary Imprint is a Ruby gem that provides signed, time-limited image rendering with dynamic watermarks. It uses HMAC-signed tokens with expiration timestamps to prevent unauthorized sharing, hotlinking, and indefinite access to images. The gem is framework-agnostic and integrates with Rails without imposing routing or controller assumptions. Images are rendered on demand using the GD graphics library, with watermarks applied dynamically. Use cases include confidential document previews, paid content protection, and temporary access to generated images. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Create Images with Ruby — ruby-libgd Dynamic Image Generation](https://daily.dev/posts/create-images-with-ruby-ruby-libgd-dynamic-image-generation-lsygteoks) · Ruby Flow · 0 upvotes · 0 comments - [Image Processing in Ruby with GD: Exploring ruby-libgd v0.3.0](https://daily.dev/posts/image-processing-in-ruby-with-gd-exploring-ruby-libgd-v0-3-0-wdpiufjm3) · RUBYLAND · 0 upvotes · 0 comments - [GitHub - wiltodelta/remove-ai-watermarks: CLI and library for removing visible \(Gemini\) and invisible \(SynthID, C2PA, EXIF\) AI watermarks from images](https://daily.dev/posts/github---wiltodelta-remove-ai-watermarks-cli-and-library-for-removing-visible-gemini-and-invisibl-oxf8kdlyr) · Hacker News · 0 upvotes · 0 comments - [Ruby-LibGD Reaches 3,000 Downloads: A Milestone in Ruby Image Generation](https://daily.dev/posts/ruby-libgd-reaches-3-000-downloads-a-milestone-in-ruby-image-generation-ltprpsxyn) · RUBYLAND · 0 upvotes · 0 comments --- Tags: [#security](https://daily.dev/tags/security), [#authentication](https://daily.dev/tags/authentication), [#ruby](https://daily.dev/tags/ruby), [#rails](https://daily.dev/tags/rails), [#image-processing](https://daily.dev/tags/image-processing) [View this post on daily.dev](https://daily.dev/posts/imprint-signed-expiring-image-rendering-with-dynamic-watermarks-in-ruby-k6k43efrq) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Imprint: Signed, Expiring Image Rendering with Dynamic Watermarks in Ruby","url":"https://daily.dev/posts/imprint-signed-expiring-image-rendering-with-dynamic-watermarks-in-ruby-k6k43efrq","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/imprint-signed-expiring-image-rendering-with-dynamic-watermarks-in-ruby-k6k43efrq"},"datePublished":"2026-01-21T22:01:50.886Z","dateModified":"2026-01-21T22:02:27.034Z","description":"Imprint is a Ruby gem that provides signed, time-limited image rendering with dynamic watermarks. 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