One of the first things a new spinner learns is that fibers for spinning come in various preparations which are called by different names and yet they all appear to look quite similar.
Asking other spinners which is which and which will usually bring a muddle of answers though all will agree that roving is carded. The fact that terms for various fiber preparations are used interchangeably to a degree doesn’t help clear up the confusion.

So, what exactly is a roving, a sliver, or a top?

A roving, according to Mabel Ross, writing in her book “The Encyclopedia of Hand Spinning” is “....a long, even strand of carded, or combed fibers which have been drawn out, then slightly twisted.” Alden Amos, in his epic work “The Alden Amos Big Book of Handspinning” states that “Rovings are slivers that have been drawn, redrawn, and run through a rover....”

Let’s sort this out: According to Amos, a roving begins as a sliver, with the sliver becoming roving as it is drawn and run through a machine called a “rover”. A rover is a machine which adds twist to the strand of sliver. Mabel Ross tells us that roving can be prepared either by carding or combing but she also mentions that the fibers are drawn and twisted.

Based on the input of these two experts, the definition of roving becomes: A long strip of fibers which has been prepared by either carding or combing and which has been drawn out and to which some twist has been added.

But, let’s backtrack for a moment and consider exactly what a sliver might be. Amos tells us that “Rovings are slivers that have been......”, which tells us that our roving was a sliver to begin with and that the sliver was turned into roving through additional processing (drawing the fiber out, adding twist). So, to define sliver, we have to look at the state of the processed fiber before the additional processing to make it into roving was done.

There are two types of sliver: Carded and Combed.

Carded sliver begins as a carded batt on a carder. What makes it into sliver is the way in which the fiber is removed from the card. Fibers removed by drafting them through an orifice which compacts them slightly and produces an even strip of fibers which contains no twist is called “carded sliver”.

Combed sliver is called Top. The difference between combed and carded sliver, other than the equipment used to prepare it, is that the combing process removes all of the short fibers, noils, and contamination from the fibers while carding does not do this. To prepare Top, the fibers are combed and then drawn off of the combs through an orifice, called a diz, which slightly compacts the fibers. So the process of making combed top and carded top differs only in the processing equipment used.

Roving is always distinguished by having a low degree of twist, and all preparations which have a low degree of twist added are technically roving. A low degree of twist may be added to both combed sliver (Top) and to carded sliver so basically, if twist is added to the preparation then it can be called “roving”. If twist is not added, then it is more correctly called either sliver (carded) or Top (combed).