What you'll need

• An iPhone for each person who will submit photos signed into iCloud.

• A Mac that stays awake, or wakes on a schedule that is also signed into iCloud.

• A sheet-fed photo printer that can be loaded with a stack of 4x6 paper and prints borderless. The Canon PRO-100 and PRO-1000 are the reference machines, and anything of that class should work.

• 4x6 photo paper in the feeder.

1. Install both apps

Install Pic Pals from the App Store on each iPhone that will submit photos, and install the Pic Pals Mac app on the Mac attached to the printer. Make sure every device is signed in to iCloud. The phones and the Mac find each other through your iCloud account, so a Mac signed in to a different Apple Account will show an empty queue with no error to explain why.

2. Start the queue on the iPhone that belongs with the printer

The first time the iPhone app opens, it asks one question — whether someone has already set this up:

• Start a New Queue — "No — this Mac has the printer." Choose this on the phone belonging to whoever owns the Mac and printer.

• Join a Family Queue — "Yes — I was sent an invitation." Everyone else chooses this.

Only one person starts the queue; everyone else joins it. It has to be the person with the printer who starts it.

3. Choose the printer on the Mac

You might not first gather that when you install Pic Pals on the Mac, there appears to be no separate app to run. The Mac app lives in the menu bar — up in the upper right hand corner icon row that is close to the date and time. You will see a little picture icon featuring a landscape scene.

Open it and click the gear to reach Settings, then pick your printer from the Printer menu.

4. Capture the paper and quality settings on the Mac

This is the step worth doing carefully. What you are doing is pre-configuring the paper profile for printing. This includes the specification of both the paper size and media type. For people new to photo printing, this is often a stumbling block. The Pic Pal iOS app guides and structures the image to print perfectly for a 4x6 print. The MacOS app sends the preconfigured print to the printer with no user intervention. This is facilitated by the paper set up in this section.

Under Paper & quality there are three configurations to capture. Click Choose… next to each:

1. Bordered photos — pick the 4x6 paper size and the photo paper type actually loaded in the feeder, for example "Photo Paper Plus Glossy II",  at your preferred quality.

2. Borderless photos — the same, but pick the borderless 4x6 paper size. On these drivers borderless is a distinct paper size rather than a checkbox. If you do not pick the borderless paper, you will have a small white margin applied by the printer automatically — the App cannot remove it; only a borderless 4x6 paper can.

3. Ink check (matte black) — pick a matte paper type here, for example Matte Photo Paper, *not* the glossy paper actually loaded. Just note, you will not be swapping papers for this printing. You are essentially tricking the printer to print in Matte Black every once in a while as the default printing on 4x6 photo paper generally only uses Photo Black.

5. Invite the family

On the phone that started the queue (i.e., owns the printer), tap Invite in the top left of the queue screen and send an invitation to each family member. This uses Apple's own sharing sheet, so invitations go out however you normally share — Messages, Mail, or a link.

Each person opens the link, taps Open when iCloud asks, and returns to thePic Pals app. Their queue then fills in.

Notes:

• The Invite button appears only on the phone that started the queue. A family member can't re-share someone else's queue, so the button isn't offered to them.

• If someone gets stuck on "Waiting for your invitation", the invitation link almost certainly hasn't been opened yet. That screen lists the three steps again and says plainly that nothing is set up yet.

• One thing to watch: if a family member opened the app and chose "Start a New Queue" before their invitation arrived, they'll have started a queue of their own. Accepting the invitation afterwards still works and takes precedence — the family queue wins — but any photos they added beforehand were added to their own queue and will need to be added again.

6. Revoking access

Tap Invite again on the phone that started the queue. Apple's sheet lists everyone who has access, and you can remove any one person or stop sharing entirely, which removes everyone at once.

Once revoked, that person's app no longer reaches the queue. Photos they already submitted stay in it — revoking access doesn't retract past submissions, so remove any you don't want printed from the Mac app's queue as well (right-click a photo, then Remove from Queue).

7. Turn printing on

Printing is off until you switch it on. In the Mac app's Settings, turn on Print automatically on a schedule. The default interval is 48 hours. Print Next prints immediately whenever you want one.

8. Turn your Camera Roll into Prints

Everyone in the family submits photos from their iPhone, choosing from a few predefined layout options: a clean white border that brings back memories of dark room developed prints, a Polaroid-inspired framing that gives you room to add details about the photos along the bottom, or simply a 4x6 print that fills the paper with your art.

The Pic Pal app provides the opportunity for previewing your photo as a 4x6 print. You have some basic controls to rotate and resize the image to look best in which ever layout you select. In the layout process, you can assign a title, reveal the location and the date-time of the photo.

If you need more extensive editing of the image, you do this outside of the App. Provided the other application (like Lightroom Mobile) can save the image back to your Camera Roll, you just need to select the edited image within Pic Pal.

When times get busy, there is the ink check

We understand life gets busy and we put our photography interests aside for a few moments. When that happens, you may fail to queue up some photos for printing. An empty queue means no prints, which defeats the purpose of exercising your printer. So when nobody has queued anything, Pic Pals prints a generated test target instead to fully test all inks in the printer.

Privacy

Pic Pals has no servers, because I operate none. Photos are stored in your own iCloud account, in a private database shared only with the family members you invite. There are no analytics and no third-party SDKs of any kind.

The app never asks for access to your photo library — it uses the system photo picker, which runs outside the app. It never asks for your location either. Location captions come from GPS data already inside the photo you chose; that coordinate is sent to Apple to turn it into a place name, and nowhere else.

Getting help

If you need additional help, feel free to submit a ticket.