This instructable is a follow-up to my previous one, which was all about making pixel art out of wood, small enough so you can decorate your desk with it. The goal of this instructable still is the same, but the method is quite different. In the previous instructable I was only able to make some roughly-shaped pixels as small as 6x6 mm. An okay start, but I I really wanted to make my pixels much more precise, and especially a lot smaller. You see, my original plan was to make a small-scale version of some pixel art from Sam & Max: Hit the Road, which happens to be my all-time favourite adventure game :) Trouble is.. the pixel art I wanted to make was over 120 pixels wide. If each pixel had a width of 6 mm, that gets you something over 72 cm wide, which makes for one humongous desk decoration.

So, in this instructable I will show you another technique that lets you make wooden pixel art, but this time with pixels as small as a single square millimeter! What's really cool is that we'll be building our own tool to cut grid patterns on wood, which makes it a whole lot easier to draw pixel art. Also, that grid-cutting tool is made out of Lego. How the brick is that supposed to work? Well, read on.. :)

Table of contents:

Tools and materials
Build the grid-cutting tool
Use the tool to cut a grid pattern
Draw the pixel art
Saw along the outline
Make a stand
Add varnish
Appendix A: Pixel art diorama
Appendix B: Isometric grids
Appendix C: Alternate designs of the grid-cutting tool
Appendix D: Pixel art gallery

Step 1: Tools and Materials

Tools:

Utility knife
Colour pencils, sharpener and eraser
Various saws with a thin blade; I used a fretsaw, a backsaw and a jigsaw. (If you have a scroll saw though, I imagine that would be even better.)
Wood rasps and files
Two spring clamps
Writing pad (or anything else less tall than 9.6 mm that can serve as a guide..)
Plunge router, to cut a dado/slot for the stand. (You can also use a drill, chisels and a mallet instead.)

Materials:

MDF wood panel (You can really use any kind of wood that you can draw onto with colour pencils; MDF works great for this purpose though.)
Some basic Lego bricks to build the grid-cutting tool, which is detailed in the next step
Stack of small Post-its
Varnish; I used a matte clear lacquer spray.

Step 2: Build the Grid-cutting Tool

To make it easy to draw pixel art onto wood, we're first going to cut a grid pattern onto it with a utility knife. Now, to make cutting the grid itself easy, we'll build our very own grid-cutting tool using some basic Lego bricks. While you could also use a steel square to draw a grid pattern, putting the square in the exact right position for each and every line can get a bit tedious. Plus, any excuse to play with Legos is a good one :)

The grid-cutting tool essentially consists of a number of 1x16 Lego beams connected to each other, with 1 Lego unit of space between each beam. You'll notice that the flat pieces connecting all the beams together go 3 units too far. This was done for a reason: You can use these 3 overhanging units to snap on a guide, which you can also put in different positions. There are two different types of guides: a single-beam guide and a triple-beam guide. Both have a different purpose, which I will explain in step 3.

There probably are several ways to build a tool like this, so it's no big deal if you don't have the exact same pieces. None the less, here is the list of bricks that I used:

Twelve 1x16 beams
Fourteen 1x2 bricks
Four 1x10 flat pieces
Four 1x8 flat pieces
Two 2x6 flat pieces
Two 2x12 flat pieces
One 2x10 flat piece
Two 1x8 smooth, flat pieces

Building the tool is straightforward; the picture in this step shows how I built mine, so I'll let it do the talking.

Side notes:

I've used Lego Technic beams here, but you could also use regular Lego beams, except for the beams used in the guides. The reason is that the knobs on Lego Technic bricks are hollowed out. This lets you attach bricks at "half" positions, which will come in handy later.

Step 3: Use the Tool to Cut a Grid Pattern

After building the grid-cutting tool, in this step I'll show you how to use it. It does require a bit of explanation, but it should be fairly easy to follow along. The tool essentially relies on the dimensions of a Lego unit, which is exactly 8 x 8 x 9.6 mm. (However, if you would measure a 1x1 brick, you will get 7.8 x 7.8 x 9.6 mm. This is because there should be 0.2 mm spacing between bricks, to prevent friction.) Knowing this, take a look the tool you've just built: It consists of a bunch beams, with 1 unit of space between each beam. The distance between the front sides of two neighbouring beams then is exactly 16 mm. (That is, 7.8 mm for the first beam + 8.2 mm of space until you reach the next beam.)

Basic usage, drawing 16x16 mm grid cells:

Knowing that the distance between each beam is 16 mm, drawing a grid with 16x16 mm cells now is easy:

Put the tool on the wood panel and place it where you'd like to cut a grid pattern.
Use one hand to keep the tool locked in place. (You can put your fingers onto the two smooth, flat pieces. It's a lot more comfortable than pushing down on Lego knobs all the time..)
With the other hand, use a utility knife to cut lines along the front side of each beam, as shown in the first picture of this step. Now you've drawn a bunch of horizontal lines, spaced 16 mm from each other. Note that you hardly need to put any pressure on the knife; just a little is enough for the lines to be visible.
Once you've carved a series of horizontal lines, just rotate the tool and you can draw the grid's vertical lines in the same manner.
Done! You've now drawn a basic grid with 16x16 mm cells.

Using the guides:

Before moving on to drawing grids with smaller cells, a few words on how to use the guides: To make it easier to put the tool exactly where you want, there are two different guides that you can use. You can attach a guide by just snapping it onto any of the 3 Lego units sticking out of the tool.

The first guide, made out of 3 beams on top of each other, is used to guide the tool along the edge of the wood panel. The second picture in this step shows the different positions in which you can attach this guide.

The second guide, which is just a single beam, is useful whenever you can't use the edge of the wood panel. The different positions for this guide are shown in the third picture. You can use this guide to slide the tool along anything that you clamp onto the wood panel. Just take a look at the fourth picture, where I've clamped a writing pad onto the wood panel with two spring clamps, such that the tool can be guided along the edge of this writing pad.

Using these two guides, you can basically position the tool anywhere on your wood panel, so you can now draw a grid across the entire panel, however large it is.

One final note about using the guides: When positioning the tool, gently push the guide against whatever you want to align it to; don't put too much force on it. If you do, the guide will start to detach, and the tool won't be in the proper position anymore. Also, while you're cutting lines, the hand that keeps the tool locked in place should only push down; don't push against the guide or, again, it will start to detach. You may be used to pushing against the guide when using e.g. a steel square, but those are made of steel, not Lego :)

Drawing 8x8 mm grid cells:

At this point you know how to draw a grid with 16x16 mm grid cells. What if you want smaller grid cells though? What about 8x8 mm cells? Well, the trick is to first draw horizontal lines every 16 mm, then shift the tool by 8 mm and simply draw another set of lines every 16 mm. (Then do the same for the vertical lines.)
The question is though, how do you shift the tool by exactly 8 mm? Not a problem: All you need to do is detach your guide, and reattach it 1 Lego unit further, which just happens to be 8 mm. Now you can draw 8x8 mm grids!

Drawing 4x4 mm grid cells:

Drawing 4x4 mm grid cells uses pretty much the same trick: Instead of shifting the tool by 8 mm, we're now going to shift it by 4 mm increments. More precisely:

First cut lines every 16 mm.
Then repeat 3 times:
- Shift the tool by an additional 4 mm by moving the guide a half Lego unit further.
- Cut lines every 16 mm.

To be able to move the guide by half Lego units, it has to be made out Lego Technic beams. The difference with regular Lego beams is that the Lego Technic ones have hollow knobs, which also let you attach bricks at half positions.

Drawing 2x2 mm grid cells

Getting trickier now.. let say we want 2x2 mm grid cells. At this small size, Lego units won't help us anymore. We'll need to think of something else to be able to shift the tool in 2 mm increments. How to make something that is exactly 2 mm thick though? Eye-balling it with a plain ruler won't cut it. After some pondering, I figured it out .. : Post-its! If I know the thickness of one Post-it, maybe I can just stack'em on top of each other and get my 2 mm. It turns out my Post-its conveniently have a thickness of 100 micrometers, or 0.1 mm. So .. 20 post-its gives me 2 mm. Just toss that stack of post-its between the guide and the tool and you can shift it by 2 mm. So, if you'd like to draw a 2x2 mm grid, all you need to do is this:

First draw a 4x4 mm grid.
Draw your 4x4 mm grid again, but always add the stack of Post-its to shift this grid by 2 mm.

Drawing nxn mm grid cells

I made most of my pixel art on a 2x2 mm grid, but using the Post-its trick, you can scale down even further! In general, here's what you need to do draw an nxn mm grid (where n is a power of 2 and 0 > n ≤ 16)

Carve lines every 16 mm.
Repeat (16/n)-1 times:
- Shift the tool by an additional n mm (by moving the guide and/or adding in the right amount of post-its).
- Carve lines every 16 mm.
Rotate the tool 90 degrees and do it all over again to draw the vertical lines.

It may look a bit complex for something as simple as drawing a grid, but you just need to get into the rhythm of cutting lines, then shift the guide a little further, drawing lines, then shift the guide a little further, and so on.. Moreover, it's really hard to mess up; you should be fine as long you don't put too much pressure on either the knife or the guide. The worst you could do is forgetting to cut a line, or cutting the same line twice, neither of which is a big deal.

Side notes:

If you want to make pixel art with 1x1 mm pixels, it's especially important that you put very little pressure on the knife while cutting. If you cut too deep, you'll risk that some of the pixels can come off, which you probably don't want.
You can also use the grid-cutting tool for more than just cutting plain grids; you can cut isometric grids as well, so you can make voxel art! Check out Appendix B (step 9) for more info.
The grid-cutting tool as-is could still use a few improvements; I'd mainly like to have longer beams. I've built some alternate designs, which do allow you to work a lot quicker, but have some other problems. If you're curious though, just have a look at Appendix C (step 10).

Step 4: Draw the Pixel Art

Once you've cut a grid pattern with the desired cell size, it's time to draw some pixel art! Go get your colour pencils and have fun :) This step more or less speaks for itself, but here are a few tips and tricks that you may find useful:

To make it easier to keep track of where you are while drawing, open up your pixel art in an image editor of your choice, then show an overlay grid grid. You should also set up the grid such that each cell is the size of a single pixel.
I used Paint Shop Pro X; in there you can enable the grid and change its settings via the View menu. If you use Photoshop, you can enable the grid via View > Show > Grid, and change its settings via Edit > Preferences > Guides, Grid & Slices... Why, even MS Paint has a grid; just hit Ctrl+G and zoom in until you get a grid cell per pixel.
When choosing the pixel art that you'd like to draw, what works best in my opinion is something with a lot of contrast and vibrant colors. Luckily, the majority of pixel art qualifies; it's not like your average military FPS where everything is some shade of brown or green :)
I like to leave a 1 pixel border around the character I'm drawing, then fill those pixels in with an appropriate background. This makes things more interesting as it gives the character some context, a world for him/her to live in.
By putting some pressure on the pencil, your carved-out grid makes sure you automatically stay within the borders of each pixel. You'll also leave a bit of spacing between the pixels. Alternatively, with less pressure, you can fill a pixel entirely, or draw across pixels. Have a look at the second picture to see the difference between these two styles. (I think I prefer to fill the pixels entirely; seems to pack more punch..) You could also mix the two styles, e.g. fill the pixels that are part of the foreground; leave a border if it's part of the background.
You have to be a little more careful when working with 1x1 mm-sized pixels; put too much pressure on the pencil and entire pixels can come off. It's better to make a couple more light passes over a pixel, rather than using more force. Also, make sure to keep those pencils razorsharp; it's a lot more comfortable than aiming for teeny tiny pixels with a blunt pencil.
If the pixel art you'd like to make has a lot of different colours, but you don't have all the exact matching colours in your box of pencils, you can usually get around this. It doesn't make a huge difference if the colours don't match exactly; you can also get away with using one colour pencil to draw the pixels of two similar, yet slightly different colours. You can create new colours by mixing different colour pencils as well. The colours won't really blend like paint does, but you'll stack the colours on top of each other create different layers of colour stacked on top of each other, which also works. Your eyes will do the blending for you, unless you look at it real closely.
Finally, be sure to take a break once in a while, just to give your eyes some rest from staring up close at the same thing all the time.

Step 5: Saw Along the Outline

In step we're going to saw along the pixel art's outline. If you happen to have a scroll saw, I'm guessing this step should be pretty straightforward. I don't have one, so I made due with a jigsaw, a backsaw and a fretsaw. The idea is to start out with a rough cut, then progressively make it more and more detailed:

First we want to make a very rough cut along the pixel art with a jigsaw. You can do this in a single cut by taking very wide curves around the pixel art. (If you happen to like the shape you get, you could already stop here, and you'll get something like the second picture in this step.) What's important here is that the surface of the jigsaw shouldn't touch the pixel art; otherwise it will smear the colours all over the place. (I should know; d'oh..) To avoid this problem, you should simply make the cut on the bottom side of the wood panel.
Once you've made a rough cut with the jigsaw, use the backsaw to cut away the biggest chunks that are easy to reach. You may or may not want to leave a little bit of wiggle room to allow for minor mistakes; we can file it off later.
Use the fretsaw to cut away the more detailed small bits, as well as the parts that were impossible to reach with the backsaw.
Finally clean it all up with some wood rasps and files. Now you can get rid of the wiggle room that you left with the backsaw.
The colours may have faded here and there during the sawing process. Go double-check and recolour where needed.

Side notes:

Here's a handy tip when making the rough cut on the bottom side of the wood panel. You can very quickly mark where you should cut on the bottom side, by roughly tracing around the pixel art with your index finger on the top side, while your other hand simultaneously copies the same motion on the bottom side, while holding a pencil. I'm basically exploiting the fact that your hands are fairly good at copying each other, even if you can't see 'em. (Oh, here's a funny experiment: Hold a pen in each hand, then try to draw the same thing on a sheet of paper with both hands at the same time, but you can only look at one hand. The copy will probably look like a slightly drunk version of the original :) .. Okay, now do it again with your eyes closed to see the really drunk version :p )
Sawing along convex parts is pretty straightforward. It's the concave bits that can be tricky. Have a look at the third picture to get an idea of what I usually do: First make two straight cuts towards the deepest bit of a concave part. Then cut the diagonals of the rectangle formed by the two cuts. Try to clean up the remaining bits with a rasp or file. If you don't have enough space to do this, you can sort of use the fretsaw as if it were a file. You basically brush the fretsaw against the wood rather than trying to saw with it.
You can avoid the recolouring part by essentially swapping this entire step with the previous one: First, draw only the pixels that are part of the outline, then do the sawing, and finally continue drawing the entire pixel art. That would probably be the smarter thing to do, but somehow I never manage to stop drawing once I've started. It's actually a very relaxing process, doing all the colouring .. probably because it's such a simple routine task, yet it's also rewarding because you know that you're continually making progress, and you can also let your mind wander at the same time, which is a good thing; that's when ideas are born :)

Step 6: Make a Stand

Your pixel art is now almost done. It can stand by itself, but it doesn't take much to knock it over, so we'll want to make a proper stand for it. Building the stand follows a similar process as the pixel art itself:

First use the grid-cutting to cool to cut a grid onto the wood panel. This way you can also draw a nice pixely floor pattern onto the stand.
Saw a basic rectangle to get a first rough cut of the stand. The small stands I made are 20x8 pixels large, where each pixel is 4x4 mm. You can use pretty much whatever saw you like for this step: a jigsaw, handsaw, .. If needed, clean up the edges with a rasp or file.
Now mark where you want to cut a dado/groove/slot/trench/.. with a knife or pencil. (If your pixel art happens to be 8mm thick, you don't even need to mark anything, as your dado then is exactly 2 pixels wide and you can reuse the grid.)
Use a plunge router to cut the dado into the stand. I just secure the stand into a workbench's vise, and make sure the stand is flush with the workbench's surface. (If you're making multiple stands, just put them all in there, as shown in the second picture.) I then attach a side fence to the router and use a small straight router bit to first cut to the desired depth, in multiple passes. Then I keep adjusting the side fence to reach the desired width of the dado. This is done in multiple passes as well; keep making passes until your pixel art fits snugly in there. (Snugly, as in: You can hold the thing upside down without the pixel art falling out, but it doesn't take too much effort to put it in the stand or take it out again.)
To make things a little more interesting, I turned my rectangles into pixelated, rounded ones by cutting away some pixels in each corner with a fretsaw. Again, use a rasp/file to clean it up.
If you like, you can colour the stand's pixels with something like a grass, dirt, concrete, .. pattern. Whatever makes sense for your pixel art. I also like to leave a few random pixels open, because I like how the light acts differently on wood than on colour pencil, which is glossier. You can also let the background of the pixel art continue onto the stand, as I did with the Sam & Max pixel art shown in the top right of the first picture.

Side notes:

If you don't have a plunge router, you can also make a dado by drilling a row of of holes closely next to each other, then cleaning the whole mess up with some chisels and a mallet, until you get a dado.
In case you accidentally cut the dado a little bit too wide, not to worry, you can easily fix it by stuffing in a few bits of paper to the back of the pixel art to get a better fit. It came in handy for me as I made pixel art both out of 8 and 9 mm MDF, so I needed some paper to fit the 8mm pixel art into 9mm dadoes.
Initially I made some ellipse-shaped stands, as you can see in the third picture. I didn't quite like how they turned out with the pixel art in there, so I started over making the pixelated stands. None the less, perhaps they may still come in useful elsewhere.. Here's how I made them: As the fourth picture shows, I first drew an ellipse with a pencil, a piece of rope and two thumbtacks. The picture also shows you how to calculate the distance between the two thumbtacks and the length of the rope, given the desired width and height. Make sure to give the rope a bit of extra length, so you have room to tie a knot. Now you can just cut out this shape with a jigsaw, clean it up with a file/rasp and cut a dado with the router.

Step 7: Add Varnish

Last step! We only need to finish up the pixel art and its stand with some varnish. You can use whatever clear varnish you like, but I applied around 4 thin coats with a can of matte clear lacquer spray. As it mainly serves to add a protection layer to the colour pencils' pigments, I only applied it to the front. The spray I used didn't noticibly alter the colours of the pixel art itself, but the wood itself did darken a little. Just let the varnish dry, and you're all done; enjoy!

Oh, just in case you're craving for more, be sure to have a look at steps 8-11, which contain a few extra ideas that extend this instructable, as well a gallery of all the pixel art I've made so far.

Side notes:

Initially I also tried some ancient buckets of varnish, which may not have been the brightest idea. (They must've been at least 10 years old, as the price tag was still in Belgian francs..) The second picture shows what happened with a Polyurethane finish, which is a bit too glossy for my tastes. The third picture was some Alkyd-based wood finish, which dulled the colours quite a lot; bad idea. In any case, lesson learned: First try the varnish on a leftover piece of wood to see what its effects are on the colour pencil pigments on and the wood itself.

Step 8: Appendix A: Pixel Art Diorama

As I was making more and more wooden pixel art, I figured it might be pretty cool to recreate entire scenes/screenshots from games, as a sort of pixel art diorama. You could create a wooden version of each character, arrange them in the scene how you want and even put them on different platforms with varying heights. You can also print the scene's background and floor pattern on sheets of paper and add those to the scene as well. Moreover, I'm building it such that you can easily tear down one scene and set up another.

I haven't quite decided which scenes I want to make yet, but the first two pictures should give an idea of what I'm going for. The first picture shows how you can arrange a bunch of different characters and platforms into a scene. The second picture shows a simple example with a background: just one character in the foreground against a paper background, which is glued to some cardboard to add strength.

The base plate at the bottom is basically made in the same way as the stands in step 6, but this one is a lot bigger. It also has 5 dadoes instead of 1, such that you you can put characters (or platforms) more towards the foreground or background. If you put multiple characters in there at various depths, the idea is that you get a slight parallax effect as you walk by the scene (i.e. stuff in the background appears to move slower than stuff in the foreground).

Making the platforms is a bit trickier. At least, it was for me, as it's the first time I made dovetail joints. The fourth picture should give a good idea of how the platforms work. Each platform consists of two pieces, joined together with a half-blind dovetail joint. The top piece also has two dadoes going through it, so you can put pixel art in there, or maybe even build platforms on top of platforms. The reason for using this type of dovetail joint is that it lets me adjust how much overhang the platform should have.
The fifth picture shows how I made the dovetail joint with a plunge router. The process is pretty much the same as using a dovetail jig that lets you cut the pins and tails at the same time, except that I used a paper template showing me where to cut instead of being guided by a jig. Here's how I made a platform with such a dovetail joint:

First saw two rectangular pieces to be used for the platforms. You can choose whatever dimensions you like, but make sure both pieces have the same length. The wood shouldn't be too thin either; otherwise you won't have enough room to cut dadoes, or the pins of the dovetail joint might be too fragile. (I used 1.2 cm thick MDF.)
To make the paper template for cutting dovetail joints, you'll need to take some measurements: First make a test cut in a piece of scrap wood with a dovetail router bit, adjusted to the desired depth.
Now measure both the maximum and the minimum width of the tail you just cut.
The paper template now consists of an alternating series of rectangles directly next to each other: first a rectangle with the minimum width, then the maximum width, then the min. width again, then max. , and so on.. I used MS Publisher to quickly draw and print this template, but you can use whatever you like, as long as it lets you precisely control the size of each rectangle.
Now you'll want to set up everything up as shown in the fifth picture. We'll be cutting the pins into the piece that is set up vertically and is secured by the workbench's vise. The tails will be cut in the piece that's set up horizontally in the middle. (It's the only piece that doesn't have a clamp attached to it.) All the other bits of wood are scaffolding to lock the tails-piece in place, as well as provide support for the plunge router.
When aligning the paper template to the pins piece, I set it up such that I start with half a pin. (You're free to shift the template left or right though; it doesn't matter much, the pins and tails will still fit together nicely..)
What is important to note is that the left side of the pins-piece is shifted a certain distance to the right, relative to the tails-piece. The distance you should shift the pins-piece is exactly: half the min. distance that you measured + half the max. distance. If you don't do this the pieces won't properly line up when you put them together.
Other than that, that's all the setup you need to do. I won't lie though; setting it all up is pretty tedious. On the plus side, making the cuts themselves is pretty quick and easy, and you can also easily make multiple sets of platforms using the same setup.
Onto the fun part; making the cuts. Attach a side fence to your plunge router, and set it up such that you're cutting along the first large rectangle of your paper template. Make sure you're as accurate as possible in setting up the side fence; if you're off a little too much the pieces won't fit together. Once the side fence is set up, go ahead and make that cut. Now readjust the side fence a little further to the next large rectangle, and make the next cut. Just keep on moving that side fence and making cuts until you reach the end, and you're all done.
Take out the two pieces and test the dovetail joint. Surprisingly, mine fit nicely every time. If they don't fit however, find what pin is causing the problem and file it down a little.
Alright, almost done: To be able to put some pixel art onto your platform, cut a few dadoes on the tails-piece. Be sure not to cut too deep or you'll interfere with the tails.
One final step: the pins-piece probably is a little too thick to fit into the dadoes of the base plate. You can easily fix this by making the bottom of the pins-piece thinner with the router. Do this in small passes until the pins-piece fits snugly. Once it does, your platform's done; hurray!

Step 9: Appendix B: Isometric Grids

Two dimensions doesn't cut it you say? Well, here's another one coming your way! Just grab your grid-cutting tool, and rotate it 30 degrees, you fool! .. Uhm okay, that's enough terrible rhyming from me :) Anyway, beside cutting regular grids with the grid-cutting tool, you can use it just the same to cut isometric grids. These are typically used for making technical drawings in 3D. In our case however, we're going to use them to make some "voxel art". (A voxel is the 3D equivalent of a pixel.)

Drawing an isometric grid with our grid-cutting tool is quite similar to a regular grid; you can do it as follows:

First cut a series of vertical lines. You can use whatever spacing you like.
Now go get something with a 30 degree angle. I got one of those 30 degree plastic triangles I used once or twice back in secondary school to practise making technical drawings. If you don't have one, just use a little trigonometry magic to put a ruler or something at a certain angle. Mathematical!
Clamp the 30 degree triangle anywhere on the side of the wood panel, as shown in the first picture. Now you can easily draw a series of lines at a 30 degree angle with the grid-cutting tool, using the same amount of spacing as the vertical lines.
Detach the clamps, flip the 30 degree triangle around, and you get 150 degrees (180°-30°). Unlike the previous step, you should now be very precise about where exactly you put the triangle. See where all the points where the vertical lines meet the 30 degree lines? Your 150 degree lines should go through those points as well, so take your time in positioning the triangle.
Once the triangle is in the right position and you've clamped it down, just draw a series of 150 degree lines, again using the same spacing.
All done; have fun drawing voxel art!

Step 10: Appendix C: Alternate Designs of the Grid-cutting Tool

In this appendix I'll show you some earlier attempts at building the grid-cutting tool and, perhaps more interestingly, also a few alternate designs to improve on the current version of the tool.

The first picture shows my first three failed attempts at building the tool: grid-cutting tools made out of wood, cardboard and roof insulation. Surprisingly, the cardboard one worked quite good actually. Either way, I included this picture just to show that, more often than not, it takes a couple of tries and dumb mistakes to get an idea to actually work, even for something as simple as drawing a grid.

The second picture is the tool I'm using right now, which is a minor iteration on the one I showed in steps 2 and 3. The main difference is that the guide has some added strength, making it more difficult to detach accidentally. The tool itself also is slightly sturdier, as each beam is connected to the 2x1 bricks with Lego Technic connector pegs.

The main aspect of the tool that can still use some improvement is the length of the beams, as the lines you can cut with them are on the short side. The third picture is my first attempt at lenghtening the beams, basically by building a bigger version of the current tool. Unfortunately these beams flex too easily when cutting lines, even if the tool is twice as tall.

The fourth and final picture is a very different attempt to improve the length of the lines you can cut. As you can see, the beams are very short, which seems a bit counterintuitive, but this tool is used in a different manner. You're supposed to use it kind of like a marking gauge, except that the knife isn't built-in. That is, rather than keeping the tool in a fixed position, you move the tool along with the knife, as you guide it alongside the wood panel. Using the tool this way actually works very well, as the beams are very short and therefore very sturdy. The only problem is that, as you slide the tool over a wood panel, some of the color of the Lego bricks gets imprinted on the wood. I haven't looked further into this yet, but I'm guessing you can easily fix this by attaching some tape underneath the tool.

Step 11: Appendix D: Pixel Art Gallery

Just to show you the variety of pixel art that you can make with this instructable, here is everything I've built so far (sorted from newest to oldest):