JPG to PDF

Combining photos into one PDF — the details that decide whether it prints right

“JPG to PDF” sounds trivial until the output lands on a printer. The three decisions that actually matter are page size, page order, and how transparency is handled. Page size: if you let each page match its image, a 4000×3000 photo becomes a 55-inch-wide PDF page that most print shops silently rescale, cropping your margins. Picking A4 (595.28 × 841.89 pt) or US Letter (612 × 792 pt) up front means the image is scaled to fit inside a real page — what you see on screen is what prints. Page order: file-system order is alphabetical, not the order you shot or scanned, so a reorder step before converting saves a re-do. Transparency: JPEG has no alpha channel, so a transparent PNG flattened onto nothing turns into black boxes; flattening onto white first is the fix. This tool encodes every image to JPEG at your chosen quality, then embeds it, which keeps a 20-photo PDF in the low megabytes instead of the hundreds.