Long before I met Rick Mondragon in person, I learned his name from an old Threads magazine article. If you have the February 1995 issue, or the reprint in Great Knits (Newton CT: Taunton Press 1995, pp. 58-61), you can read his article "Knit in Blocks of Color -- without Bobbins." Rick's technique allows you to knit individual blocks and then connect as you go. In that regard it is similar to modular knitting, except you really are ending up with the yarn in exactly the same place it would be if you had lined up a long row of little balls or bobbins and knit not-so-merrily across in intarsia. And if you are a Kaffe Fassett fan, this technique could open up a whole new world!
One way to learn this is to knit two plain intarsia blocks and then unpick only one of them. (The white dots are the tops of the pin heads. I've pinned this swatch flat to a pillow.) I've unpicked the top eight rows of knitting on the blue half of this swatch. Do you see the paired yarns? (The yarn all by itself at top is the working yarn connected to the skein.) Each of those four pairs is a long loop. Each loop comprised two rows of knitting, one out (the right side row) and one back (the wrong side row). The genius in Rick's idea is the realization that you could pull yarn through the turning threads on the back and create proper intarsia interlocks after the fact.
In this view of the wrong side, you can see each loop of blue interlocking with white.
Rick does teach this technique from time to time. I, however, have not had the good fortune to take his workshop. (Lois Mitchell, the AKG librarian and NGKG past treasurer, has taken the workshop and given it a fine review.) So I gave myself I little extra help. Lucy Neatby uses waste yarn a fair bit to aid in visualizing grafting. I decided to use waste yarn to aid in finding those turning threads and pulling the loops of yarn through in the proper direction. I worked across, then I used a little waste yarn to work two waste stitches beyond the current section. I worked those waste stitches as I would for normal intarsia. When I went back to add the next section with the precious Schaefer Laurel, I unpicked the pink waste yarn each row as needed and used the loop as a guide.
The photograph above shows the front of the work. Since this piece is worked to follow a graphed pattern, the stitch marker corresponds to a division on the graph paper. The photograph below shows the same piece folded down to reveal the back. Can you see how the pink waste stitches are forming perfectly normal intarsia interlocks? (That pink dashed line is the key.)
Although I am sure this gets easier with practice, I would characterize it as a more advanced technique; and I probably wouldn't use it if good old regular intarsia would work fine. But in this case, it helped me get the Schaefer Laurel to pool in a way that I liked and without forcing me to waste a lot of yarn.
There are limitations. Rick's technique works for square, rectangular, or tapered shapes. But it does not work so well for overhanging cliff shapes, because you would have to cast-on the overhanging stitches rather than work them into established stitches. You do have to plan your shapes carefully if you want to work this way. Also, how you attach loops is slightly different depending on whether you are adding to the left or the right side of a section. If you are interested in further exploring this technique, you might want to knit a sample swatch with three sections and unpick both sides but not the middle.
On the positive side, Rick's technique can be used to do some really amazing things. If you are working a gridded multi-color fabric in the style of Kaffe Fassett, you have more freedom to add on colors and rip back. And this technique permits true intarsia in the round. Seamless argyle socks are not impossible!