Making the Internet of Towels (IoT) with Lenticular Images & QR codes

(Left image) Internet of Towels when viewed head-on/flat; (Right image) Internet of Towels when viewed at a 45-degree angle.

Technique#1: Lenticular Images

Lenticular images in postcards (Image source:
(Left) How autostereoscopic lenticular displays work (image source:; (middle) Lenticular barrier technique with paper folding (image source: (right) Shadow/illusion knitting (image source:

Technique#2: QR Codes

An example of contemporary uses of QR codes for COVID-19 vaccine passports (image source:
The screenshot is taken from the peer-reviewed article “Fast-Component Based QR-Code Detection in Arbitrarily Acquired Images” by Belussi & Hirata (2013) (

Combining the two techniques

Lenticular crochet

In my first trials with shadow crochet, I tinkered with the height of the lifted blue stitches for each row.

Data Matrix

Experiments with a 10x10 data matrix — the stitches were misaligned, it did not work great!

QR code

I used Microsoft Excel to make the lenticular yarn pattern for the 25x25 QR code. Two cells/stitches = one pixel of the QR code.

Make a lenticular towel pattern for your custom QR code using the Yarn Arts Software

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Reference books and articles




Researcher, designer, crafter of things

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Anuradha Reddy

Anuradha Reddy

Researcher, designer, crafter of things

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