# IDP Smart 21 vs 31 vs 51: ID Card Printers Compared
The IDP Smart range is one of those product lines where the model numbers don't tell you much on their own. You've got three printers that look broadly similar, sit at different price points, and serve genuinely different use cases. So here's the honest breakdown — what each one actually does, who it's for, and where the money goes.
The Quick Version
If you're in a hurry: the Smart 21 is a simple, affordable single-sided printer for low volumes. The Smart 31 adds dual-sided printing, encoding options, and handles mid-range workloads. The Smart 51 is a higher-capacity machine with faster throughput, more encoding flexibility, and a larger input hopper. That's the shape of it — but the detail matters.
Smart 21: The Starter
The Smart 21 is IDP's entry-level card printer, and it does what an entry-level printer should do — prints single-sided cards cleanly without asking too much of your budget or your patience.
It's a single-sided printer only, so if you need printing on both sides you'll want to look further up the range. Print speed sits around 150 cards per hour for full-colour YMCKO prints, which is perfectly reasonable for a small office, a school reception, or a sports club that issues a few hundred cards a year.
The input hopper holds 50 cards. Connectivity is USB only — no network option. And there's no encoding of any kind, so if you need mag-stripe, smart chip, or contactless encoding, this isn't your machine.
Who it's for: Small organisations printing under 2,000 cards a year. Visitor badges, basic staff IDs, membership cards. You don't need bells and whistles — you need a card with a name and a photo on it.Smart 31: The Middle Ground
The Smart 31 is where the range starts to get interesting. It's available in both single-sided and dual-sided configurations, which immediately opens up more design possibilities — photo on the front, barcode or info on the back, that sort of thing.
Print speed is similar to the 21 for single-sided work, but the dual-sided model handles both sides in a single pass, which keeps things moving. The input hopper is the same 50-card capacity.
The big difference is encoding. The Smart 31 supports magnetic stripe, contact smart chip, and contactless encoding modules. So if your cards need to do something beyond just looking presentable — open a door, store data, work with an access control system — this is where you start.
Connectivity upgrades too: USB as standard, with an optional Ethernet module for network printing. That matters if the printer is going to be shared across a department or managed by IT.
Who it's for: Organisations printing 2,000-10,000 cards a year that need dual-sided printing or some form of encoding. Schools, corporate offices, healthcare settings, gyms with membership systems.Smart 51: The Workhorse
The Smart 51 is IDP's high-volume machine, and the jump from the 31 is more than incremental.
The input hopper doubles to 100 cards — which sounds modest until you're standing over a printer feeding cards one handful at a time. Print speed climbs to around 200 cards per hour for full-colour single-sided, and the dual-sided model keeps a solid pace too.
All the encoding options from the 31 carry over, plus the 51 handles them with better throughput. Connectivity includes USB and Ethernet as standard (not optional), and there's a Wi-Fi module available if you need it.
Build quality is noticeably sturdier. The 51 is designed to run longer print jobs without overheating or jamming, which is the kind of thing you only appreciate after you've experienced the alternative.
Who it's for: Organisations printing 10,000+ cards a year. Universities, large corporates, government agencies, healthcare facilities — anywhere cards are issued regularly and downtime isn't an option.Feature Comparison
| Feature | Smart 21 | Smart 31 | Smart 51 |
|---|---|---|---|
| Print sides | Single only | Single or Dual | Single or Dual |
| Print speed (colour) | ~150 cards/hr | ~150 cards/hr | ~200 cards/hr |
| Input hopper | 50 cards | 50 cards | 100 cards |
| Resolution | 300 DPI | 300 DPI | 300 DPI |
| USB | Yes | Yes | Yes |
| Ethernet | No | Optional | Standard |
| Wi-Fi | No | No | Optional |
| Mag stripe encoding | No | Optional | Optional |
| Smart chip encoding | No | Optional | Optional |
| Contactless encoding | No | Optional | Optional |
| Annual volume | Up to 2,000 | Up to 10,000 | 10,000+ |
All three use the same IDP Smart ribbons, though each model has its own specific ribbon SKU — make sure you're ordering the right one. The 21 uses Smart 21 ribbons, the 31 uses Smart 31 ribbons, and the 51 uses Smart 51 ribbons.
What About Software?
All three printers work with IDP's own card design software, and they're compatible with most third-party ID card design packages too. The printer driver handles the heavy lifting, so your choice of printer doesn't lock you into a particular software ecosystem.
That said, if you're doing encoding — particularly smart chip or contactless — you'll want software that supports it. Worth checking before you buy.
Running Costs
This is the bit people often overlook. The purchase price is one thing, but the per-card cost is where the real spend lives. All three models use YMCKO ribbons for full-colour printing, and the cost per print is broadly similar across the range. The difference is volume — if you're printing 10,000 cards a year on a Smart 21, you'll be replacing ribbons and cleaning rollers far more often relative to the machine's expected lifespan.
Match the printer to your volume. It's the single most practical piece of advice for any card printer purchase.
Which One Should You Buy?
There's no trick here. It comes down to three questions:
1. How many cards per year? Under 2,000 — Smart 21. 2,000-10,000 — Smart 31. Over 10,000 — Smart 51.
2. Do you need encoding? If yes, Smart 31 minimum.
3. Do you need dual-sided printing? If yes, Smart 31 minimum.
If you're unsure about volumes or you think your needs might grow, stepping up one level is usually a better investment than buying the cheaper machine and replacing it in eighteen months.
Browse the full IDP Smart range to see current pricing and availability, or give us a call if you'd like to talk through which model fits your setup.
