Ribbon replacement is the most routine maintenance task for any working typewriter, and it's one of the more confusing ones for newcomers. The physical ribbon — a fabric or film strip inked with carbon or nylon — is simple enough. The spool it winds onto is where things get complicated. Spools vary in hub diameter, outer diameter, and attachment mechanism across manufacturers and eras, and using the wrong one produces inconsistent feed, ribbon jams, or print that fades before the ribbon is remotely depleted.
This guide covers the main spool standards, which machines use which, how to identify an unknown spool size, and what the genuine limitations of universal spools are.
The two things that have to match
When fitting a ribbon to a typewriter, two dimensions need to be correct:
- Ribbon width. The vertical height of the ribbon strip. The most common standard for manual portable typewriters is 1/2 inch (12.7mm). Some machines, particularly pre-war uprights and specialized office machines, use narrower (7/16 inch) or wider (13/16 inch) ribbons. If the ribbon width is wrong for the machine's ribbon guide and type slugs, the ribbon either won't cover the full strike area or will foul in the guides.
- Spool hub diameter. The center post that the spool slides onto. On most machines from the 1940s–1970s, this is one of a small number of standard diameters. The spool has to seat firmly without wobble — loose spools feed unevenly and can walk off the post during operation.
Outer spool diameter matters less for function (as long as the spool fits under whatever cover or housing the machine has) but affects how much ribbon fits on the spool. A spool with more capacity isn't inherently better if its outer diameter is too large to fit the machine's housing or spool cover.
The major spool standards
Standard spool (most common: 2-inch outer diameter, 7/16-inch hub)
This is the type of spool used on most American portable typewriters from the 1940s through the 1970s: Royal, Underwood, Remington, Olivetti (later models), and many Smith Coronas. The hub is roughly 7/16 inch in diameter. The outer diameter of the spool flange is approximately 2 inches. If someone mentions a "standard typewriter ribbon" without further specification, they typically mean this format.
Smith Corona-specific spool (smaller hub, thin flanges)
Many Smith Corona portables from the 1950s and 1960s — Silent, Silent-Super, and several of the Galaxy and Galaxie models — take a spool with a slightly different hub configuration than the Royal/Remington standard. The physical dimensions are close enough that standard spools can be forced onto SC machines, but the fit is sloppy and ribbon advance becomes inconsistent. Smith Corona ribbons sold specifically for those models fit the spool posts correctly and are worth the extra sourcing effort for a machine you use regularly.
Olympia/Adler large spool
German machines, particularly Olympia SM series portables (SM2, SM3, SM4, SM7, SM9) and various Adler Tippa models, often take a slightly larger spool format with a bigger outer diameter. These are sometimes called "typewriter size A" spools in European supply catalogs. Universal ribbons frequently don't seat properly on Olympia posts, which is a common source of complaint from Olympia owners who buy generic ribbons without checking. An Olympia SM3 or SM4 specifically needs a spool that fits the wider-set posts on the right and left of the platen carriage.
Brother/SCM (post-1970 compact portables)
Compact portable machines made from the 1970s onward — including many Brother portables and late-model SCM machines — often use a much smaller plastic spool with a different center tab design. These spools clip onto the post differently than the earlier metal spools, and ribbon wound on the older standard metal spools typically won't feed correctly in these machines. If you have a 1970s or 1980s compact machine, confirm you're buying ribbons made specifically for that era of compact portables.
Office-class uprights (different again)
Full-size office uprights from the 1950s through the 1970s — IBM, Royal HH, Underwood Champion — often take larger format spools with more ribbon capacity, sized for heavy daily office use. The spool posts are frequently in a different position and orientation than portable machines. If you're restoring an office upright, confirm the spool format before ordering. IBM Selectric machines are a category unto themselves: they don't use a ribbon spool at all but instead use a cartridge (fabric ribbon loop) or an element-and-tape system, depending on era.
| Machine type | Common ribbon width | Hub type | Universal spool compatible? |
|---|---|---|---|
| Royal / Underwood / Remington portables (1940s–70s) | 1/2 inch | Standard 7/16" | Usually yes |
| Smith Corona Silent / Silent-Super / Galaxie | 1/2 inch | SC-specific | Marginal — works but loose |
| Olivetti Lettera 32, Studio 44 | 1/2 inch | Standard 7/16" | Usually yes |
| Olympia SM series | 1/2 inch | Olympia-specific | Often no — get Olympia-specific |
| Hermes 3000, Baby | 1/2 inch | Standard | Usually yes |
| Post-1975 compact portables (Brother, SCM) | 1/2 inch | Plastic clip style | No — needs compact-specific |
When universal ribbons are genuinely fine
Universal ribbons work well on machines in the Royal/Underwood/Remington/Olivetti family — which is a broad category that includes many of the most commonly found vintage portables. If you have a standard-hub machine and you're buying any ribbon explicitly sold as 1/2-inch universal typewriter ribbon on a standard spool, you'll get acceptable results.
The ribbon material matters more for print quality than the spool format. Cotton ribbons give a softer, less precise impression. Nylon ribbons print sharper and last longer, and they're what most new-old-stock ribbons from surviving suppliers use. For most everyday typing, nylon is the better choice. If you're after a particular aesthetic — softer, drier impression with slight ink variability — some people prefer cotton. The cotton/nylon distinction will be listed in the product description on reputable suppliers.
When universal ribbons fail
Universal ribbon failures happen in a few predictable scenarios:
Olympia machines
The spool post dimensions on many Olympia portables don't match the standard American hub size. A universal spool seated on an Olympia post will wobble, and the ribbon advance mechanism — which requires friction from a properly tensioned spool — won't function correctly. The ribbon either stops advancing or advances unevenly, producing faded impressions across a single line.
Machines with integral spool housings
Some machines, particularly certain 1960s–70s designs, have spool wells that are shaped to hold a specific spool outer diameter. A standard-size universal spool with a slightly different outer diameter than expected may jam in the housing or spin freely without engaging the advance mechanism.
Re-inking old spools
An alternative to buying new ribbons: re-inking the existing ribbon using typewriter ribbon ink (sold in small bottles, applied to the ribbon while it's run through slowly). This works well for nylon ribbons that aren't physically worn out but have simply dried. It doesn't work for ribbons with worn fabric structure or for film (carbon) ribbons, which are one-time-use by design. Re-inking is worth knowing as an option for machines whose spool format makes sourcing commercial replacements difficult.
Actually replacing the ribbon: the mechanical process
The process varies by machine but follows a consistent logic across most portable manuals:
- Note the threading path before removing anything. Photograph it or draw a quick sketch. The ribbon feeds through at least two guides — one on each side of the type basket — and the exact path is not always obvious once the old ribbon is out.
- Release the old spools. Most machines have a friction-fit or light clip that holds spools on their posts. Some have a small locking tab. Remove both spools together with the old ribbon still threaded.
- Transfer the threading path to the new ribbon. New ribbon spools come with the ribbon on one spool only. Thread the free end through the guides in the same path the old ribbon used, and attach the empty spool to the take-up side.
- Set the ribbon selector. Most machines have a two- or three-position selector for black, red (if using bi-color ribbon), and stencil. Confirm it's on the black position before testing.
- Advance a few turns by hand and test. Type a few characters on scrap paper to confirm impression, coverage, and consistent advancement.
Bi-color ribbons (black/red)
Bi-color ribbons are still available for most standard spool formats. The top half of the ribbon is black, the bottom half red. The machine's ribbon selector shifts the ribbon guide up or down to bring the correct color into the strike zone. If your machine has a bi-color selector lever, a bi-color ribbon will work in it. If you use a single-color ribbon in a bi-color machine, just set the selector to the black (upper) position and the red position will strike blank fabric.
Where to buy ribbons that actually fit
General-purpose online retailers carry universal ribbons that work on the common Royal/Underwood/Remington family. For Olympia-specific, Smith Corona-specific, or machines with unusual spool requirements, the better sources are typewriter specialty suppliers who specify exact machine compatibility. eBay is worth checking for new-old-stock ribbons in original manufacturer packaging, which sometimes fit machines that current universal spools won't. Searching by machine model rather than "universal typewriter ribbon" produces better results for anything outside the standard American portable family.
Gear actually worth buying
Ribbon and maintenance supplies for working typewriters. We earn a small commission on qualifying eBay sales; your price is unchanged. Full disclosure.
Universal typewriter ribbon (1/2" spool)
Standard 1/2-inch nylon ribbons on a universal spool fit most American portables (Royal, Remington, Underwood, Olivetti, Hermes). Check spool hub if you have a Smith Corona or Olympia.
Smith Corona-specific ribbon
Ribbons sold specifically for Smith Corona Silent / Silent-Super / Galaxie models seat correctly on the SC spool posts. Better advance consistency than forcing a universal spool.
Olympia SM ribbon
Olympia SM3, SM4, SM7, and SM9 machines need Olympia-specific spools. Universal spools wobble on the posts and cause advance problems. Check eBay for new-old-stock Olympia ribbons.
Typewriter ribbon re-ink fluid
Re-inking a dry nylon ribbon is cheaper than replacing it. Apply ink to the ribbon while slowly advancing it by hand. Works well if the fabric is intact; doesn't help worn-through ribbon.
Digital calipers
A cheap digital caliper ($12–18) measures spool hub diameter and outer dimensions precisely. Useful for any typewriter repair work, and for confirming a replacement spool will fit before ordering.