2026 Remote Mac iOS App Icon Delivery Matrix: Full-Size PNG, Contents.json & sRGB Acceptance

① Size & role matrix (PNG pixel targets)

Ship square PNGs at exact pixel dimensions listed below. Xcode maps each file via Contents.json; do not rely on “Retina scaling” inside the asset catalog to fix a wrong master. Keep one vector or high-resolution master (e.g. 1024 px design grid), then derive sizes—on Apple Silicon, batch resizes complete quickly thanks to high memory bandwidth and efficient CPU/GPU paths in native exporters.

Align color conversion with your wider PNG policy in Mac PNG color management: sRGB vs Display P3 so icon batches do not drift from marketing stills.

② Contents.json contract

AppIcon.appiconset/Contents.json is the handoff contract between design and Xcode. Each entry in the images array should declare idiom (iphone, ipad, ios-marketing), size (point size string such as "60x60"), scale ("1x", "2x", "3x"), and filename. The marketing 1024 slot uses idiom: "ios-marketing" with size: "1024x1024" and scale: "1x".

• Single source of truth: After designers drop PNGs, run plutil -lint Contents.json on the remote Mac to catch trailing commas and typos before CI.
• No orphan files: Every PNG in the folder should be referenced; every filename entry should exist on disk.
• Version pin: Commit the JSON alongside PNGs so “which catalog layout?” is always diffable.

③ Superellipse mask, alpha & “flat” delivery

iOS applies the rounded-rectangle (superellipse) mask at render time. Deliver fully square PNGs with artwork extended to the edges unless your team explicitly uses a different internal template; do not bake iOS corner radius into the bitmap for production App Icons. Keep logos and faces inside a central safe region so the mask does not clip critical detail.

Alpha channel: The App Store 1024×1024 marketing icon must not use transparency—Apple rejects alpha on that slot. For smaller slots, prefer fully opaque icons unless you have a documented exception; accidental semi-transparent pixels often come from anti-aliased “rounded” exports or checkerboard backgrounds. Treat “unexpected alpha” as a release blocker and fold it into the checklist below. For broader PNG alpha governance, see OpenClaw PNG QA: batch transparency checks on remote Mac.

④ Executable export parameters (sRGB)

Standardize these parameters across Figma, Sketch, Affinity, and Photoshop so every derivative is comparable:

⑤ Acceptance checklist (design + front-end)

⑥ Batch validation on M-series & remote Mac

On Apple Silicon, looping over ~15–20 small PNGs is trivial; the win is repeatability and running checks while your laptop is offline. A remote Mac can host the same scripts under a fixed macOS + tool versions, mirroring how studios pin batch PNG QA.

Step A — dimension sweep (folder):

for f in *.png; do
  echo -n "$f "
  sips -g pixelWidth -g pixelHeight "$f" 2>/dev/null | paste -sd ' ' -
done

Step B — flag alpha on the marketing icon: use ImageMagick identify -verbose on [email protected] (or your 1024 file) and assert the alpha channel is absent; fail the build if rgba appears.

Step C — manifest: emit icons_manifest.csv with path,w,h,bytes,has_alpha,colorIntent and attach it to the release ticket. For high-throughput export jobs that surround icon work, batch 4K PNG export on remote Mac M4 describes queue discipline that scales to large asset drops.

Parallelism tip: when generating from a single 1024 master, run independent resize jobs in parallel (xargs -P)—M-series machines handle multiple concurrent sips or CLI resizers well within thermal norms for short bursts.

Summary

Use the pixel matrix as the single sizing contract, keep Contents.json linted and aligned with filenames, enforce sRGB export parameters across tools, and treat alpha on the 1024 marketing icon as a hard failure. Pair design review (mask/safe zone) with scripted batch checks on an M-series Mac—ideally a dedicated remote Mac—so icon drops stay boring and shippable.

Next steps: remote Mac for design delivery

Browse plans on the MacPng homepage, then open rental options and pricing to add a remote Mac node for icon batches, PNG QA, and long-running validation without blocking your primary workstation. The help center covers SSH/VNC onboarding for distributed teams.