Who publishes this site
Print Prep Lab is an independent educational project created and maintained by Hossam Eldeen. He is responsible for the calculator logic, page content, corrections and public project tracker. The site is not owned by a print shop, paper manufacturer, standards body or software vendor.
That independence is important: examples are written to explain the decision behind a print calculation, not to promote a particular laboratory or product. External references are identified on guide and source pages rather than presented as endorsements.
Why Print Prep Lab exists
Print questions often mix pixels, DPI, PPI, paper size, crop and bleed into one confusing answer. Print Prep Lab separates those decisions, keeps the relevant formula visible and lets a visitor reproduce the result from the same inputs.
The project is intended for photographers, artists, students, small businesses, Canva users and print customers who need to check a file before paying for an order. It focuses on the gap between a digital image's pixel dimensions and a physical product's trim size.
What the calculators actually do
The tools convert physical units, calculate required or available pixels, compare image and paper aspect ratios, estimate crop retention, and build bleed and safe-area dimensions. Standard paper presets are stored in physical units so the pixel result is generated from the PPI selected by the visitor rather than copied from a fixed chart.
When an image is selected, its width, height and temporary preview are read locally by the browser. The file is not intentionally sent to a Print Prep Lab server. The same calculations can also be used by entering dimensions manually.
How results are checked
The mathematical functions have deterministic tests covering unit conversion, PPI, crop, bleed, rounding and invalid input. Public pages are also checked for distinct titles, descriptions, canonical URLs, working internal links and a single main heading.
A public issue template asks for the exact inputs and expected result when a discrepancy is reported. This makes a correction reproducible without requiring anyone to share a private image.
What this site does not promise
A browser calculator cannot inspect a printer, ink, paper profile, sharpening method, color conversion or production tolerance. A numerical result can show that a file meets a selected pixel-density target, but it cannot certify the finished print.
The company producing the work remains the final source for bleed, minimum resolution, color profile, file format and proofing requirements. Print Prep Lab deliberately labels common values as planning targets rather than universal rules.
Contact and corrections
Calculation problems, missing formats and page errors can be reported through the public GitHub Issues link on the Contact page. Reports are most useful when they include the page, numerical inputs, orientation, selected unit, expected result and any relevant provider specification.
Privacy, editorial process, sources and terms are linked from every page so visitors can see who is responsible for the site and how its guidance is produced before relying on a result.
Verify the project, publisher and calculation code
The claims on this page are backed by public project records rather than by invented credentials. These links show who maintains the project, where the calculation code lives and how arithmetic defects are tested.