The critical step for inlaid dovetails is cutting a rabbet 1st on the tails board ( inside face ). For inlays it is mandatory. The depth of the rabbet determines the thickness of the inlay line all around. I usually make mine around 3/32- 1/8” thick.  I will be using  3/32”.  

Set your marking gauge to the thickness of the inlay board and scribe a line across the width of the tails board. Next set your marking gauge at 3/32” and scribe a line on the end grain and the sides. Then remove the meat as shown here in Fig 6 . I usually use a chisel and my router hand plane.

Next, I have set my marking gauge depth to thickness of Pin board as shown in Fig 7. Then I lightly scribe a line all the way around on the Tails board as shown. Be careful not to cut too deep. It’s better to scribe lightly and then darken with a pencil.

 

Then I complete the layout the spacing for the Tails and Pins per Fig 8. When choosing the size for the tails remember you need to allow for the actual finished inlay outline that you want. Normally your tails should be a little narrower because the inlay outline will add width to it. As previously mentioned, this will be 3/32” (0.094”). Therefore at the bottom of each cutout (as measured from the gauge line made) I chose to make this spacing at 7/16” as shown. I highly advise you to pencil everything out so you can be sure it’s what you want before cutting.

 

In Fig 9, I use a ratio of 1:6 to mark out the Tails from the 7/16” spaces made.

 

Next, per Fig 10, I make knifewalls which are key in guiding the saw blade and making accurate cuts. You could use a jig or trust your ability to cut down the line.

As seen in Fig 11, the sawing begins and the Tails are cut.

 

Here in Fig 12  you see the completed cut rabbet and tails.