I am essentially lazy and am willing to spend hours figuring out how to save myself (and you) ten minutes.
In order to minimize the finishing work for my Kitties on My Lap Blanket pattern, 
After knitting a lovely version of the Kitties on My Lap Blanket as a wedding present, lovely knitter Betty (Bettyilene on Ravelry), asked if there was a way to weave in ends on a purl row similar to the method I used on knit rows in the pattern.
If the purl row is on the wrong side (like in stockinette fabric), absolutely. In fact, there are at least two ways of weaving in the ends on a purl row. If it is on the right side, the weaving in will definitely show. If someone has figured out how to do this without it showing, please leave a comment below!!!
As when weaving in ends on a knit rows, weave in the old colour on the row where you are changing yarns, weave in the new colour on the next purl row. You can finish weaving in on the next knit row if you have more yarn end to weave in.
Also, as when weaving in ends on a knit row, pierce the yarn when you first start to weave in to further secure the end.
For both methods, pull the end taut after working to even things out and then stretch the fabric to maintain appropriate stretch one blocked.
I will be demonstrating by weaving in a contrasting colour on a solid background to make it easier for you to see. The weaving in is much more visible than if you were weaving in the yarns at an actual colour change.
Watch the video or follow the instructions below the video.
Method 1:
When you work the first stitch, pierce the yarn end to secure.
*Purl one stitch.
Lift the yarn end up between the needles and the working yarn, purl the stitch. Drop the yarn end.
Repeat from * until you have woven in enough yarn to make you comfortable. If you still want to weave in more yarn at the end of the row, weave in as for a knit stitch.
Method 2:
Work the first stitch on the row, piercing the yarn end as you do.
*Before working the next stitch, flip the yarn end over the working yarn from right to left and leave hanging on the purl side of the work.
Purl the next stitch.
Repeat from *.
Note: For both methods, alternatively, insert the right needle tip into the next stitch as if to purl, then life the yarn end over both needles and finish the stitch.
Try both methods and see which you prefer, both in terms of doing the movements and in terms of how the finished product looks and behaves.
Before you block your piece, pull the end taut to even things out and then pull the fabric out to where it will need to stretch to. This will ensure that the weaving in is neat and that the stretchiness of the fabric is maintained.
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