These pieces were done in Continental Stitch, and you can see, if you have an old piece lying around on a footstool, chair seat, or bell pull, the ugly horizontal ridges that resulted. It was a relaxing occupation for women, as they knew no other stitch. The Penelope canvas, being double woven, was strong enough to hold this stitch without too much distortion. Mono-canvas is not. Even for people who work on a frame, the distortion is pretty bad. (It's also pretty boring to stitch) There is also the factor that Continental stitch makes a flimsy, thin needlepoint fabric as opposed to the well padded and smooth one created with basketweave. For ecclesiastical work - as cushions and kneelers, if a canvas thread breaks from heavy use, or rots after a number of years, if done in Continental stitch, the stitches will fall out. If done in basketweave, the stitches hold. Incidentally, I have never used a frame, as I see no need for it - by learning so long ago the proper method of stitching basketweave, my canvases don't warp.
The illustration is of a piece I did last night for this "lesson," and is a repeat of something I used for years to teach (without the continental stitch swatch, of course) beginners. It's easy to see the ridges on the left, and also the bit of distortion already beginning even on this little 1 1/2" square. We used to dread having a person in a class who had done continental stitch previously, as the concept of diagonal was difficult for them to learn. I have taught classes of five-year-olds who learned easily in a few minutes - so it's really quite simple. Both my daughters, and my granddaughter learned by watching me for a few minutes at about ages 9 or 10, and then went off to their rooms and did it beautifully - so it is NOT difficult or mysterious.
In the 70's we put quite an emphasis on beautiful, smooth surfaces, and these ridges you can clearly see on the swatch above on the left were not acceptable - so everyone learned basketweave, which gets its name from the appearance of the back.
Basketweave on the left - Continental on the right. Where I put the arrow, you can see the place where the trip back across (actually "half cross") from left to right wraps under the one horizontal thread, which is what gives it the ugly ridge. I am told that some people turn the canvas upside down for the trip back, trying to avoid this ridge - but that isn't good either, as it pulls loose some of the fibers from the threads of the row below. This is as poor a practice as doing Algerian Eye by coming up in the center hole. (another of my pet peeves, which just involves a little common sense.)
Also, if you hold up a swatch like this to the light, you can see horizontal gaps on the one stitched with continental. The light shines through. Basketweave is solid. In this close-up illustration, the ridges are clearly seen on the left swatch.
I included the little patches of basketweave and the "scroll" to illustrate that it can be done on tiny little areas. I actually read in a popular book recently that "you can't do basketweave in small spaces." This is a ridiculous statement! My little practice teaching pieces used to consist of just such irregular, odd-sized small patches, and also some scrolls and squiggles and gently curved lines for understanding the concept of outlining. No need to call it anything else - it's just "outlining" with a bit of basketweave where the scroll thickens.
In this business of needlepoint, as with other things, there are preferences and opinions, and there are facts based on experience, experiments, trial and error, and just plain common sense. In my 40 years of designing, teaching, and writing about needlepoint, I have always been willing and eager to try new things and suggestions with an open mind, and figure out simple and effective ways to do things (like my beading techniques). If you aren't convinced that Continental stitch is not right for use on the painted canvas on Mono-canvas, just stitch a swatch yourself and see the difference!!. I have no answers for why on earth it is being taught again. I thought we had done away with it for good at least 35 years ago. Oh dear.