The one-paragraph answer
Infrared (IR) touch senses with a light grid in a frame around the display; projected capacitive (PCAP) touch senses with an electrode grid in a film or glass layer on the display. IR scales to any size and works with any object; PCAP gives a flush glass surface and phone-style gestures at small-to-medium sizes. Most specification errors come from choosing by habit instead of by the four variables below: size, surface, object and environment.
Variable 1 — Size
PCAP economics collapse as area grows: the catalogue's PCAP range ends at 27 inches, which is typical for the technology's cost curve, while the IR frame programme runs 15 to 500 inches. Between 15 and 27 inches both technologies are real options. Above 32 inches, IR is effectively the default; below 15 inches, PCAP is effectively the default.
Variable 2 — Surface
PCAP's surface is its own tempered cover glass: flush, sealed, printable — the right face for a product. IR's surface is whatever protects your display, plus a frame profile standing a few millimetres proud. If the design cannot accept a bezel lip, or the front must wipe clean as one plane, PCAP (or foil behind existing glass) wins. If the surface must be replaceable in the field, IR wins — the sacrificial glass is yours, not the sensor's.
Variable 3 — The touching object
IR responds to fingers, gloves of any kind, and passive styli. PCAP responds to bare fingers and capacitive styli; glove operation exists as tuned modes on some panels but must be specified, not assumed. Surgical, industrial and winter-outdoor contexts therefore lean IR; consumer-style products lean PCAP.
Variable 4 — Environment
Strong direct sunlight can disturb IR receivers; heavy electrical noise and water films are PCAP's traditional adversaries (modern controllers mitigate both, at a price). Indoor, shaded, dry: either works. Declare the hostile factor in the inquiry and we will specify against it rather than discover it with you.
| Infrared frame | |
| Size range (this catalogue) | 15″–500″ |
| Touch object | Any — finger, glove, stylus |
| Surface | Frame profile on existing display |
| Multi-touch | 10–64 points |
| PCAP panel | |
| Size range (this catalogue) | 7″–27″ |
| Touch object | Bare finger / capacitive stylus |
| Surface | Flush tempered glass, printable |
| Multi-touch | 10 points |
Still torn? Send the four variables — size, surface requirement, touching object, environment — through the inquiry form and the reply will name a technology and a model, with the reasoning.