If you're printing one color prints, well, you cut the linoleum block, slap a piece of paper on it, trim the paper and you're done.
If you want to do multiple-block printing, you have to have some way to line the edge of the paper up every time, so that, say, the red background printed from block 1 lines up with the black foreground printed from block 2. This is called registration.
Step 1: What a Shoddily Made Jig Looks Like
I used this jig to print the intro print and hundreds of others over the last couple of years. I threw it together out of scrap wood and stuff around the house, quickly and terribly, and it's held up forever with no particular signs of wear.
The wood edges here between the area where the printing block goes and the cardboard "guardrail" is 3/4 of an inch. I want to make some bigger prints with a bigger border, so I'm making a 1" jig and a 1.5" jig.
Step 2: Gather Pieces, Mark, and Sand
This one will be a 1" border jig to print 6 x 8 blocks on 8 x10 paper. What I had kicking around was an 11 x 11 piece of 1/4" thick masonite and some ends of 1 x 2s.
I measured 1" on the flat part of the 1 x 2 (which is really a .75 x 1.5, remember) and sanded up the shinyish surface of the masonite. The masonite may be a little too slippery once I start printing, making the block a little slidey, but I can scuff it up or add a coat of rubber spray paint or something later.
Importantish: linoleum blocks are mounted on 3/4" deep blocks, so the .75" deep 1 x 2 works well. It doesn't need to be exactly that deep, but if it's much deeper the paper won't reach the edges of the block, and if it's too shallow the paper will arc down on the edges of the block (damp printmaking paper droops), making the registration less accurate.
(See Figure 2, where you can see the height of the block vs. the 1 x 2, and which also gives a sneak peek at the clumsy finished solution.)
Step 3: Glue, Fondle, and Clamp
I used Elmer's white glue because the wood glue had been sitting for a year and got weird. I'm sure the white glue'll be fine.
Get some paper towels and rip off a couple, because your hands are gonna get gluey.
Press the wood into the glue and feel around the edges with your finger to make sure it's flush with the edge of the masonite. This is most important for the first piece, in the upper-left corner.
Clamp 'em down and tidy up the drippy glue. I use dollar-store clamps. I love clamps.
Step 4: Make the Guardrail, Let Dry If Neccessary, and Make Some Prints!
For the 1" jig, I didn't have any thumbtacks, which probably would have worked, but I did have some small nails, so I made the guardrail out of those. Make sure to take into account the width of whatever you're using -- you want the side of the nail to line up with the line on the board, so don't center the nail on the line, but put it a little to the outside.
And look! Here's our special guest, a 1.5" jig I (mostly) prepared earlier. This doesn't need measuring or nails (you line up the 1.5" wide 1 x 2 flush with the edge of the masonite), so I just made a guardrail out of a double layer of strips of cardboard stolen from the back of a pad and glued together. Glue is the strongest material known to man.
As with the 1 x 2s, feel the corners to make sure they're flush with the edges of the masonite. You kinda don't have to, really, but you might as well. I also put in some staples with a staplegun for the heck of it.
That's it! Hope this was helpful.
Your pal El Rey
Step 5: Optional Step: the Bench Hook
A bench hook kind of anchors the jig to the edge of the table so it doesn't slide around. I did this for the much earlier 3/4" jig, but might not for these, since I'm now printing on a round dining table.