The roll is not the hand-in
A series lives on a phone, a card, a folder named `final-final-3`. The person who must look at it — a tutor at 23:40, a gallery intern, a print-on-demand clerk — wants one PDF, in order, that opens without a plugin.
Images to PDF is the contact-sheet table: JPG, PNG and WebP together. Drop order is volume order. If the sequence is the story, sort the files before they hit the bench. Pdfmira does not guess a narrative from filenames.
iPhone frames, mixed plates
HEIC from the camera roll still breaks half of campus forms. Convert the series to JPG first, then impose. Live Photos and depth maps do not travel: you get the still.
A PNG of a diagram in the same PDF as portraits is fine. Transparent grounds usually flatten to white on the sheet — like paper. If you need the checkerboard, keep the PNG beside the PDF, do not expect the impose to preserve alpha.
Already have three short PDFs — cover, plates, colophon? Merge PDF stacks them as signatures. Do not rasterise them into images just to glue them: merge keeps vectors if they were vectors.
What the recipient actually opens
A photographic PDF can still be too heavy for mail. Compress PDF after you like the preview, not before: you cannot judge a contact sheet from a 200 KB smear. Screen stock is for screens. Print stock is the one you take downstairs.
This is not a magazine imposition: no automatic folios, no bleed, no reader’s spreads. For a true lookbook grid, stay in the tool that made the grid, then hand in that native PDF. Pdfmira is the bench for people who have photos and a deadline.