Terms of Service

Introduction

Welcome to GraphiteGuild (“we,” “our,” or “us”). These Terms of Service (“Terms”) govern your use of our website at pencilbrush.com and all associated calculators, guides, and services (collectively, the “Service”).

By accessing or using the Service, you agree to be bound by these Terms. If you disagree with any part of them, please do not use the Service.

Acceptance of Terms

By accessing, browsing, or using GraphiteGuild, you acknowledge that you have read, understood, and agree to be bound by these Terms and our Privacy Policy, which is incorporated by reference.

We may update these Terms at any time. Your continued use of the Service after changes are posted constitutes acceptance of the revised Terms.

Educational Aids — Verify Before You Rely

GraphiteGuild’s calculators are learning and reference tools. Several apply deliberately simplified, transparent formulas (explained on each tool’s own page) rather than a certified physical measurement, so a result depends on your input and on those stated assumptions. Nothing on the Service is professional art-conservation, materials-science, or manufacturing certification. Before you rely on a result for a graded assignment, a bulk paper purchase, or any purpose where precision matters, confirm it against the manufacturer’s own specifications or by testing on scrap material.

Description of Service

GraphiteGuild provides free, browser-based calculators and educational resources, including:

• A graphite grade (H/B) guide mapping the standard 9H–9B hardness scale to a darkness index
• A paper weight/gsm calculator across bond, text, cover, and index basis stocks
• A perspective grid generator for 1-point and 2-point perspective
• A proportion and grid-transfer calculator for scaling reference images
• A value scale generator producing an evenly stepped grayscale strip
• A pencil-to-page size guide for scaling between ISO 216 paper sizes
• Guides, explainers, and reference content on drawing fundamentals

All tools are provided free of charge. We may modify, suspend, or discontinue any part of the Service at any time.

Your Responsibilities

When using the Service, you agree to:

• Use the tools in good faith for learning, practice, or personal projects
• Enter values in the correct units and check that your inputs describe a valid setup
• Not disrupt, overload, or attempt to compromise the website
• Respect intellectual property rights

You are responsible for exercising your own judgment and for confirming important results before relying on them.

Accuracy and Disclaimers

While we aim for correct, well-sourced formulas, we cannot guarantee that every calculation is error-free or suited to your circumstances. Results are estimates based on standard conventions and the figures you provide, and are rounded for display. GraphiteGuild makes no warranties, express or implied, including implied warranties of merchantability, fitness for a particular purpose, or non-infringement.

Intellectual Property

All content on this website — text, graphics, logos, tools, calculators, and software — is the property of GraphiteGuild or its content suppliers and is protected by applicable copyright and other laws. You may use the tools for personal and educational purposes; you may not copy, resell, or reverse engineer them, or remove proprietary notices.

Limitation of Liability

In no event shall GraphiteGuild or its suppliers be liable for any damages (including, without limitation, wasted materials or other losses) arising out of your use of, or inability to use, the Service, even if we have been advised of the possibility of such damages.

Third-Party Links and Ads

The Service may link to third-party websites and displays third-party advertisements. We do not control and are not responsible for their content, and inclusion of a link or ad is not an endorsement. Your use of any third-party site is at your own risk.

Governing Law

These Terms are governed by and construed in accordance with the laws of the United States, and you submit to the exclusive jurisdiction of the courts located there.

Contact Information

• By email: support@pencilbrush.com
• Via our contact page