Scanning Old Postcards Without Moiré: Halftone 133–175 lpi Bench

When scanning old postcards, you often see a wavy, grid-like visual distortion covering the image. This interference is called moiré. It occurs because most vintage postcards were not printed as continuous-tone photographs, but rather mass-produced using a commercial halftone printing process, typically ranging between 133 and 175 lines per inch (lpi). To successfully remove moiré when scanning old postcards, you must capture the image at a high optical resolution of at least 600 DPI, apply a precise digital descreening algorithm, and slightly blur the halftone dots back into a smooth, continuous photograph before applying final sharpening.

The Science of the Moiré Effect on Vintage Postcards

If you have ever attempted to digitise a treasured collection of early 20th-century holiday postcards, you will likely have encountered the frustrating moiré effect. Unlike standard chemical photographs, which feature a continuous tone of silver halide crystals or dyes, vintage postcards were almost exclusively printed using lithography or offset printing. To reproduce gradients and shades using solid ink, printers translated the image into a matrix of microscopic dots of varying sizes—a technique known as halftone.

The standard density for mid-century postcard halftone printing in the UK and Europe was between 133 and 175 lines per inch (lpi). When you place one of these printed cards onto a modern digital scanner, a structural conflict occurs. The scanner’s sensor features its own fixed grid of pixels. When the mechanical grid of the halftone dots overlays the digital grid of the scanner’s sensor, the slight misalignment generates a third, completely artificial pattern. This is moiré: a sweeping, oil-slick-like ripple of concentric circles or aggressive cross-hatching that completely ruins the aesthetic of the scanned image.

For those looking to learn more about how flatbeds interact with various media, you might find our guide on how to scan old newspaper clippings incredibly helpful, as newsprint suffers from a very similar, albeit coarser, halftone problem.

Home Flatbeds vs Lab Descreening: The Halftone Bench Test

Most consumer-grade multi-function printers and cheap standalone photo scanners completely lack the hardware logic to handle halftone prints. They are designed for modern documents or modern glossy photos. When a consumer device attempts to scan a 150 lpi postcard at 300 DPI, the aliasing is mathematically guaranteed.

To fix this, professional labs employ a technique called "descreening." This is not a simple blur filter, but a targeted frequency separation technique. The lab scanner captures the postcard at an exceptionally high optical resolution—often beyond 600 DPI—so that the sensor accurately resolves every individual ink dot without aliasing. Then, specialised software analyses the frequency of the halftone pattern (calculating the exact lpi) and applies a micro-blur strictly at that frequency to melt the dots together, before using edge-detection sharpening to restore the borders of the subject.

For more on hardware resolution testing, read our breakdown of the best negative scanner UK 2026, which explores the vast difference between box claims and measured lab resolution.

Protecting the Handwriting: Front and Back Scanning

One of the greatest tragedies of amateur postcard digitisation is ignoring the reverse side. A postcard is a physical artefact of correspondence. The photograph on the front tells you where your ancestors were, but the cursive handwriting, the postmark, and the stamp on the back tell you who they loved, what they felt, and exactly when they posted it.

When you send your postcards to EachMoment, they are treated as loose photo prints. Our technicians handle these delicate historical items with cotton gloves, ensuring that the oils from human skin do not degrade the century-old paper. We strongly recommend digitising both sides of significant family postcards to preserve the complete historical record. The combination of beautiful, moiré-free imagery and preserved handwritten sentiment makes for an unparalleled family heirloom.

If your postcards have taken on a heavy sepia tone over the decades, you might find our article on scanning sepia photos highly relevant for understanding how base colour affects digital restoration.

The EachMoment Memory Box Process

Digitising your vast collection of family memories has never been simpler, thanks to the EachMoment Memory Box system. You do not need to worry about sourcing expensive flatbeds, learning to use descreening filters, or spending hundreds of hours scanning one card at a time.

When you place an order, we ship a crush-proof Memory Box directly to your UK address. You simply fill this box with your postcards, loose photo prints, video tapes, and cine films. A trusted courier collects the filled box from your doorstep and transports it securely to our state-of-the-art digitisation lab in Croatia. Here, our expert technicians—who have digitised over a million items—process your media using our extensive, lab-grade equipment chain.

Once the digital transfers are complete, your files are loaded onto a USB stick or formatted onto DVDs, depending on your preference. We then safely package your original media back into the Memory Box and courier it straight back to your home in the UK.

Pricing: What Does Postcard Digitisation Cost?

At EachMoment, postcards are classified and priced as standard loose photo prints (up to A4 in size). We believe in completely transparent, volume-based pricing. The base price for digitising a postcard or loose print is £0.39 per photo. However, our system applies generous, stacking discounts based on the total value of your order, making bulk family archiving highly cost-effective.

If you return your Memory Box to us within 21 days of receiving it, you automatically qualify for our 10% Early Bird discount. In addition to this, we offer volume thresholds that scale up the more you spend. For example:

• Orders over £75 receive an additional 10% off.
• Orders over £150 receive 15% off.
• Orders over £250 receive 20% off.
• Orders over £500 receive 25% off.
• Orders over £1000 receive a massive 33% off.

Because the Early Bird and volume discounts stack multiplicatively, larger archives can achieve up to a 43% combined discount on the base price. If your postcards are heavily faded or damaged, we also offer an AI-restored Full HD enhancement add-on for £4.99 per item, which uses advanced algorithms to breathe incredible new life into degraded imagery. We also handle obscure vintage formats; for instance, read our guide on digitising 1982 Kodak disc pictures.

FAQ: Scanning Old Postcards

How do I stop moiré patterns when scanning postcards?

To stop moiré patterns, you must scan the postcard at a very high resolution (at least 600 DPI to out-resolve the halftone dots) and apply a digital descreening filter. Standard home scanners often lack the hardware capability to do this effectively, which is why professional lab digitisation is highly recommended for halftone prints.

Can I just blur the image to remove the halftone dots?

While a basic Gaussian blur will reduce the visibility of the halftone dots, it will also destroy the edge detail, text, and overall sharpness of the photograph. Professional descreening uses frequency separation to blur only the halftone pattern while preserving the sharp edges of the image.

How much does it cost to digitise a postcard?

At EachMoment, postcards are priced at our standard loose photo print rate, which is £0.39 per photo. This base price can be significantly reduced by utilising our Early Bird discount (10% off) and our volume discounts, which offer up to 33% off for larger orders.

Do you scan the back of the postcard as well?

Yes. We can treat the back of the postcard as a separate scan. Because the back often contains vital historical context—such as handwriting, stamps, and postmarks—digitising both sides is the best way to fully preserve the memory.

Where are my postcards sent for scanning?

You pack your items into our secure Memory Box at your UK home. A courier collects the box and transports it directly to our specialist digitisation laboratory in Croatia. After our technicians process your media, your original postcards and your new digital files are securely couriered back to you.

Can AI enhancement fix faded postcards?

Yes. We offer an AI-restored Full HD enhancement for £4.99 per item. This optional add-on uses advanced artificial intelligence to restore faded colours, improve contrast, and sharpen details that have been lost to decades of sunlight and environmental degradation.