Before printing: Set scale to 100% (disable 'Fit to page'). If colors print grey or blank, check the printer's own color and quality settings — no browser checkbox is needed.
BYTESCOPE · PRINTER TEST PAGEA4 (210×297 mm)
One sheet that shows what your printer is doing wrong — color, black ink, alignment and hairlines, printed straight from the browser's own dialog.
Your files never leave your browser — all processing is local.
Before printing: Set scale to 100% (disable 'Fit to page'). If colors print grey or blank, check the printer's own color and quality settings — no browser checkbox is needed.
Hit print and this page sends one diagnostic sheet to your printer through the browser's own dialog — window.print(), no PDF service, no upload, no account. The sheet packs solid CMY and RGB patches, composite black next to pure K, a stepped gray ramp from 0 to 100%, a heavy black coverage field with dense text at shrinking sizes, corner-and-center alignment crosshairs with margin rules, and hairlines down to a fraction of a millimeter. Switch between A4 and US Letter and the size is applied through the @page CSS rule, so the print dialog picks it up on its own. An ink-saver mode prints only the alignment and hairline sections — enough to confirm the printer works at all, without burning a color cartridge to find out.
The color patches make a starved or clogged channel obvious: missing magenta turns patches green long before you would notice it in a photo. Composite black — CMY mixed — sits right beside pure K, so a black that prints brownish tells you which side of the system is off. Each step of the gray ramp should be visibly distinct and dead neutral; banding or a color cast here is the printer, not your eyes. The solid black field and the shrinking text catch a failing black cartridge or blocked nozzles as streaks and fade-out. The corner crosshairs and margin rules expose paper skew and feed problems, and the hairline block — horizontal, vertical and diagonal lines at descending widths, plus tiny text — shows exactly where head alignment and registration give out.
Be clear about the limits: a web page cannot talk to your printer. Color management, driver settings, the printer's quality mode and any "fit to page" scaling all sit between this sheet and the paper, so treat it as a comparison tool for spotting a problem — not a calibrated color target. Print one sheet while the printer is healthy and keep it; when output looks wrong later, print another and hold the two side by side. For the alignment grid and hairlines to mean anything, turn off "fit to page" and set the print dialog to 100% scale. One setting you can ignore is "Background graphics": every patch, ramp and hairline here is drawn as an SVG shape — foreground content, not a CSS background — so it prints whether that box is ticked or not. That is deliberate; the sheet should not depend on a checkbox most people never find.
Not the "Background graphics" setting — the blocks on this sheet are SVG shapes, so they print as regular content whether that option is on or off. Look at the printer instead: a driver set to grayscale or "print in black and white", a draft or toner-save quality mode, or a color cartridge that is empty or clogged — which is exactly the fault this sheet exists to expose. Fix the setting or swap the cartridge and print again.
Neither. The sheet is plain HTML and CSS rendered by your browser and handed to the printer through window.print() — the same path as printing any web page. There is no PDF generator, no server in the loop and no account; nothing about you or your printer leaves the machine.
Whichever paper is actually in the tray. The switch sets the size through the @page CSS rule, so the print dialog should follow along automatically — but glance at the dialog's own paper-size field anyway. If the two disagree, the browser quietly rescales the whole sheet, and the alignment and hairline sections stop meaning anything.
Check scaling before blaming hardware. If the print dialog is set to "fit to page" or anything other than 100%, the browser rescales the sheet and every mark on it moves. Set scale to 100%, turn scaling off, and print again. If the crosshairs are still skewed relative to the paper edge after that, it's real — likely a feed or head-alignment problem, and worth running the printer's own alignment routine.
No — it shows you the problem; the fix lives in the printer. Run the head-cleaning or alignment utility in your printer's driver or on-device menu, then print this sheet again and compare. Streaks in the black field that shrink after each cleaning pass mean you're getting somewhere; a color that stays missing after several passes usually means the cartridge or printhead itself is done.
Test your display for dead pixels, color uniformity, response time, and backlight bleed.