Basics: How to get good, clean, straight cuts in XPS Foam (Black Magic Craft Episode 030) 

Based on my quilting experience - which involves lots of detailed and "fussy" cutting, I'd suggest cutting while standing rather than sitting. I find it easier to get accurate cuts on many layers of fabric by standing over it.

Just a little tip to add to your knife technique. If you do end up with a slight bevel, put the smaller side down. That way the top surfaces will still butt tight together.

Having cut thick material for a living, i would recommend getting a weighted ruler, or if they are too expensive, get an iron bar cut down to match the length of your ruler and adhere it to the ruler using epoxy or some other adhesive. This prevents the knife from pushing the ruler around as you cut.

I had been planning on making dungeon tiles as a thank you gift for the people who volunteer as DMs at my local comic shop. Thanks to your videos they are now getting double sided 1/2" foam tiles instead of the 1/4" printed and mod-podged foam tiles I was planning on making! Instead of just giving them a functional gift now I think they will be getting something they can really appreciate and integrate into their own games. Thanks man! :)

Man I should have done my homework. I’ve been a fan but I never thought to start from the beginning with your basics. I donated and did the Dice Tower build. It is a very cool project, but I was butchering some XPS with a $20 craft store foam cutter, a PVC saw and one pass cuts with a ratcheting blade. I made three bases. The one I covered so far ended looking nice, but a bit rough, almost like a goblin tower. The multi pass cut I just tried (even with a dull blade) is so much smoother. It would have saved me a lot of time and heartache. Now I know. Keep up the good crafting! Thanks again for working with St. Jude!

Great stuff. I mainly use a hot wire tool for cutting large pieces of foam. Only foam core is cut with my hobby knife. I like that blade you demonstrated in the video as well as the method of cutting it.

Once again awesome video, I've been having alot of issues cutting the pink foam cuz all I have is a knife. But you have given me some great tips. Now I feel better on it. Thank you my friend

Rockin! I have also done some mitered cuts with the Proxxon table. You need a protractor to set it up, but works aces.

I was just trying this and it works perfectly with lining up my metal ruler with the cutting mat to get great pieces using a razor blade! Thanks, I was so frustrated trying to get the cuts right!

This is so great! I'm taking an architecture class and getting ready to model a rammed earth structure. Amazing tips. Thank you!

I can always recommend one of these kitchen knife sharpeners (those round ones made from metal) if you do a lot of work with the cutter knife. If the blade gets a bit dull, use it and you are ready to go again. Makes your blades last longer and you won't have to change them as often. Withe the added benefit that it saves you some money, especially if you use more expensive blades. (which I always recommend as the cheap ones simply don't work that well with foam)

Thanks for the list with good XPS suppliers! I've literally been searching for days, but to no avail. Recently came across your channel and there's a lot of great stuff on there, so I subbed straight away and pretty lucky that you covered this subject now.

Thanks for this. I WAS trying to cut foam with an xacto knife, which was tearing, and I wondered what I was doing wrong. Will try using a razor utility knife and see if that works better. Thanks again!

a good trick to make a 90°-Cut on thick material: use a strait, well sanded block of hardwood, instead of a ruler and keep the knife strait at the side of the block. (does not work with too flexible knifes). Hobbyknifes doesn't cut so easy in hardwood, so it works.

I like the straight foward approach you use.

Thank you for all your help getting started in this hobby. Go Jets!

Hi, came upon this and took your recommendation on the proxxon and couldn't be happier. thanks for the great video! I am off and running with it...making some scale structures for a bunch of projects and this provides real nice, light weight building material...

Great idea on the depth gauge! Never thought of that before

Great tute. Heres a quick FYI for your safety. I highly recommend investing in a chef's/meat cutters Cut Glove. They are gloves made from Kevlar that will not let a knife penetrate or slice thru to your hand. There are also chain male gloves that meat cutters use to keep all their fingers Intact. You can find them for like $5 or $6US on eBay. You get one good slip of the knife you can seriously gouge you can loose fingers. These gloves have helped save my hands for over 30 years of modeling.

Fantastic tutorial, I don’t have a hot wire cutter so your tips on knife cutting was very helpful. Thanks

I keep a sharpener on hand to get the most out of my blades. Thank you Bill Doran and Evil Ted for teaching me that trick haha

Drafters/artist want that cork strip or thick tape on the back of the ruler so when they run a marker across the ruler, the ink does not bleed under the ruler.

Burnings in New Zealand also stock the same brand of xps as they sell in Australia.

I've been using a crappy exacto knife and getting rough edges, but honestly, I have been making it work quite well IMO. It creates a rocky effect around the edge of the dungeon tiles, wouldn't be good for more detailed things, but for the ground beneath a layer of stone in a dungeon, it works. Also, I used 1 inch instead of 1/2 inch material for those tiles, and it was my first try.

From 2017, and still helpful. Thanks!

Menards Local Store, I got three quarter inch thick XPS for 12 dollars for 4 foot by 8 foot sheet. They also cut down the sheet into 4 feet by 1 foot slabs for me, so I could get it home without being blown away by the wind.

I use a serrated steak knife. I like the 'rough' looking edge as it makes it look more like stone.Will probably use the box cutter for things I want more refined or nicer looking.

If you want a REALLY cheap hot wire cutter and like to get inventive... you can actually run a current to an olfa knife/blade and heat it up to make your cuts. I wouldn't say it's necessarily "better" but I've found it's faster and seems to help the blade stay sharper longer.

that cutter is amazers

holy hell my man. ive been practicing and racking my brain about why my frickin cuts are just never perfectly straight for a couple days now. glad to know it isnt exactly all me

Thanks again for that advice. Good thing I watched this video before starting to build up my terrain. ;)

Let's cut the crap! Thanks for sharing such useful information! Exactly what I was linking for. Working on a boat project.

Thank you so much for the techniques and demonstration!! Great info!

You hit the nail right on the head. I made my first batch of dungeon tiles using a box cutter and although it did work, it was a lot of work, and getting the tiles nicely square was just a pain in the ass. Making a whole bunch of squares at the same time (4 x 4) did help speed it up a bit though. I did have lots of jagged edges since my knife wasn't very good, but you couldn't really see it in the end because you roughen up the tile anyways. When I got a hot wire tool it was suddenly so much easier. The end result does indeed not look very different, but it saved me so much time. Making squares you only need to set the distance right once, then you can just first cut long strokes of foam, give them a quarter turn and cut again. Cutting thin strips is really difficult to get done nicely imo, but with a hot wire table it is a piece of cake. Great advice, I fully endorse this :)

Nice video, glad I'm not the only one having problems with angle cuts:) Just ordered the table and your razor set from your shop. Hopefully, the fee amazon pays you compensates for the beating I'm going to get from my wife ...LOL Seriously, it was the best price I found:)

You are "Best Teacher Ever."

Another great video! Good work.

"Let's cut to the chase" Lol.....I love it!

Any pointers on cutting curves with a blade? Like doorway arches, for example. Great video! Keep up the great work!

Holy cow..that machine is perfect!

I find a 10" T-bevel handy. I can mimic angles for layout, and [at least for small pieces] I have a steel straight edge at the ready.

B&Q has different types of XPS foam in the UK, though can potentially be a little pricey depending on shop location.

I forgot to like this one, sorry! Error corrected. Sometimes, going back to basics helps a lot. Thank you!

Keeping your blades sharp is the most important factor, BUT I suggest getting something like a sharpening stone, I have one next to me when ever I'm cutting things and do a light pass on the stone every 4-5 min while cutting something that dulls the blade fast like Styrofoam. that said I still use a hotwire cutter pridominatly when dealing with styrofoam.

Where has this video been all my life?

I had no idea hot wire tables existed! I know what i wanna get myself for christmas now! I was making shabby cuts with a saw blade and xacto knife and smoothing them with a mini belt sander, terrifyingly 😂

ive used exacto knives for cutting my tiles for years. no problems at all. perfect cuts. its all in the technique.

J, this video is great. I wish I had it a year ago!

I wandered to your channel absolutely accidentally, but this is such a treasure. Your way of explaining is so clear and really engaging. Thank you a lot! (and please, in the future use some protection gloves or something working with the hot wire, bc my level of anxiety reached extreme markings watching you do it with your bare hands! I was worried you would cut your arm through!!)

For a perpendicular cut using the razor knife, I'd try taking the blade out of the knife and clamping it to a known right angle object (say, a piece of wood) and using that along with a straight edge.

Hey man, love the videos and I love the work you create. It's opened up a whole new experience for me and a very nerd hobby. I do not have the space for a hotwire table though, as much as I would like one. I was wondering if you wouldn't mind eventually making a few videos based purely when using a knife. A hot wire table is clearly the more efficient and precise way but it'd be good to watch and learn from purely knife based techniques. Either way, inspirational shit man

Just messing around, I tried this foam in some of my woodworking tools. My table saw cuts this to a factory finish with no tearing, so I decided to step up a notch. Believe it or not, you can feed this stuff through a thickness planer with zero issues. The only things I find don't work well are spinning bits. Drill presses and routers tear it apart.

Thank You for all this tips :)

I already have a woodworking bandsaw so I use it to cut my styrofoam pieces. It's a little messy but works great!

Can't wait to build my HeroQuest tiles!

XPS Foam: For Greece, you can find it as "θερμομονωτικό φελιζόλ", "Εξηλασμένη Πολυστερίνη", "Styropan XPS", "φελιζόλ styropan" etc. Its available at almost relatively big craft stores (I get it in a local one), including Practicer, Leroy Merlin etc. If researching for prices, pages like skroutz. gr can compare prices from physical shops & e-shops all over the country.

The taller your straight edge the more perfectly vertical your cut will be i.e. if you use a half-inch square rod as your straight edge you can keep the knife flush with the edge and be vertical.

Awesome thanks!

You and brent are great

Evil Ted Smith uses a Kershaw Blade Sharpener to extend the life of his blades. He builds eva foam costumes, the stuff dulls blades like crazy. I picked one up and its super nice.

Cheers! It's funny that, whilst it's easy with practice to cut a 2x4 square with a hand saw, even easier to cut thinner timber with a back saw, and cut a mortice plumb with a chisel, it does seem odd that a knife tends to angle like that in softer material. Do you think it might be because of body mechanics? We often cut timber whilst bearing over the board with our body, looking down on the cut, and chop with a mortice chisel whilst standing back to judge plumb. My woodworking bench is quite low, my sawhorse is even lower. Do you think crafting whilst hunched at a desk might be to blame for off square cuts?

Good instructions!

Bandsaw is also an option to cut different foam boards and you don't get toxic fumes. Downside is the crumbs but they can be get rid of with vacuumcleaner. Small bandsaw can be bought for $120+ and they can be used to cut all kind of materials not just foamboards. I have used bandsaw for cutting styrofoam and it works wonders. I like your videos and keep watching them.

I own a proxxon wirecutter, but it turned out being too slow for big parts (I was building big foamcore/fibreglass sandwich parts for the interior in my selfmade RV). I ultimately ended up using a jigsaw with a thin aluminum blade - works like a charm. As far as I've heard, a bandsaw with a thin blade does the job, too (and also with perfectly straight angles). I once was cutting with one of those larger knives like shown in your video and ended up in the ER to get some stiches: The knife got stuck for a microsecond and when it quickly got free again I ended up swinging it towards my other hand that was holding the part and cut a good cm deep, down to the bone. Oops.

Watching these basics videos as I get ready to go to Dollarama and Michaels 😅

A bandsaw makes quick work of thick foam and the mess is containable if you use a saw with a dust collector. The hot knife can make a closed shop’s air quality pretty dismal.

Guess I know what I need to ask for for Christmas...lol

great, thanks!

Great videos - I bought the Proxxon on your rec for cutting XPS and it's great but I'm wondering if you have tips for cutting a curve (like a large arch). I have some ideas, but I'm wondering if theres a way to use a template that doesn't get cut with the foam or another method. Does making a shallow blade cut first help? (I know I should be experimenting but I thought I'd ask a pro) Freehand is way too impossible for me.

I went cheap and bought a Styro Cutter for about $9.00 from Hobby Loppy. Does the same job as the foam cutter youre talking about. That being said i mostly just cut with my blade and yes good blades matter a lot.

I recently bought a aluminum fishing boat and I have been seeing videos of people using this to help make flooring to stand up easier in the boat .. my question is .. if you took a two-by-four and put it under each outer edge and stood on the middle so that the foamular board bent about 2" like the letter U , how much pressure would it take before the board snapped .. how much can it Bend before breaking more or less .. the reason I am asking is because the bottom of the boat has a little bit of a V shape and isn't perfectly flat .. I'm sure I can use something to fill in the center to make it where the board wouldn't bend much but I think it would still have a little Bend to it .. also how well can you sand the edges to round them off

Olfa +1. I first came across an Olfa cutter while working for a sign company, and the yellow plastic had a whole bunch of red acrylic paint on it, made me remember to be careful to not cut any fingers off...lol Olfa blades are amazing, but first time users...safety tip, go real slow, these things are extremely sharp, and try not to work alone, because if you do cut yourself, you can do some serious damage if you are not paying attention... (Raises hand, shows scars) Why is it Olfa cutters always seem to be some of the ugliest, beat up, misused, tools? They pretty much last forever...looks like you're using one with a black handle almost, but I could see the yellow peek they in some spots... I think you almost have me convinced on the proxxon, but I doubt it will happen before xmas...rock on.

For your standard dungeon tiles, do you use 1/4", 1/2", or 3/4" XPS? I also found that my contractor's table saw cut through the 1/2" foam with no problem and it came out very smooth.

Would I be able to cut a piece of foam to 12" x 12" using the fence?

Hi, I've been watching a whole bunch of your videos, including the whole beginner 'track'. Love it! And I started working on my own tiles to practice. I also made a water well as the first centerpiece during my previous D&D session. The players loved it, although it was a very simple piece. Now, why do I reply to this specific 2 your old video? Because I'm stuck on making a specific cut: a 6x6 tile piece... For my 3x3, I was able to use my proxxon to halve my 2cm foam I could find here in Belgium down to 1cm tiles. But how in the world am I supposed to make the thinning cut on a 6" block? It doesn't fit the cutter. Let alone the 12x12 piece you sometimes mention. How do you do it? Or do you keep the original block thickness? I appreciate all the work you've done recording all of this inspirational footage over the years!!

It just occured to me to use a piec of 2/4 ontop of the metal straight edge as a guide to keep the angle of the cut uniform along each pass. the metal straight edge would still keep the blad on target. and the 2x4 would be where the blade handle would ride along?

I was wondering how to cut a design out of this foam , not a straight line , i carved out a design out of this foam using a exacto blade and your right it dulled it and the exacto blade wasn't 2 inches long anyway to finish , so i had to use a really sharp thin kitchen knife to cut the rest i took my time and it came out pretty good a little rough around the edges , i didn't think i could sand this foam with out destroying it , but you can actually sand it , i sanded out all the rough edges and any other imperfections , and it looked perfect . But it was a lot of work and i was thinking if i had a rotary type tool or something to make the cutting easier and more precise would be better for a future project , i now have a Dremel but not sure if it would work you really have to have a steady hand but the Dremel works for carving design into the project , haven't tried it yet , that's what brought me here to your video .

You could use a thicker metal bar instead of a ruler and run your blade alongside it to maintain a 90 degree cut.

Great advice! Also... new camera (DSLR)??? Lookin' good!

Thanks mate

How do you recommend working with the XPS if you get a 4x8' sheet from a store? What is the best method to cut these? Do you recommend cutting them into a certain size so you can work with them on the hot wire table?

Hi, i've been building a few terrain pieces out of xps and learned a lot from you. I still got a question ( maybe you already addressed it ): Do you remove the factory surface ( not a coating but simply the little bit harder, shiny surface with the logos )? Apart from the indented logos i found that the cut surface holds details or tin foiled-structure much better and also appears to be matte when painted. If you do - have you any special tips how to cut down large tiles (like 12x12 or your huge irregular cave tiles)? Thanks a lot!

Just came across this video. Great tips. I’m going to get the Olga knife. Do you use the 18 mm or 25 mm size? Thanks again.

To make 90 degree cuts, instead of a ruler, I use a 1 "x 1" aluminum angle.

Love all of your videos dude, I've been watching you almost daily for about 3 weeks now and have found all of your content suuuper inspiring keep it up! In regards to purchasing and acquiring XPS I was wondering if there were any alternatives that won't just crumble and make a mess like styrofoam? I am struggling to find where to get XPS foam here in New Zealand. I have seen that it's available at bunnings in Australia, but there is limited stock of this here in NZ, I've tried using styrofoam but all I end up doing is making a mess and crumbling tiny foam balls everywhere. Any NZ crafters whom know where to get good quality foam? Specifically in Hamilton.

just commenting on the most recent video so it can be seen. painting tile pieces ( like your dungeon tile) for outdoor like grass or sandy, is it the same process?

Is there an easy way you can cut a thick plate into 2 or 3 thinner ones without using the thermo cutter ? I cant get the 1 or 2 cm ones here.

What is the best way to make cuts on a large sheet? If I have a 2" x 4' x 8' sheet, what is my best method for cutting it down to more usable sizes? (I've been using a circular saw and guide, not sure it's the best though)

I realize this is an old video and people are unlikely to see this, but it's worth a shot. Does anyone know of a left-handed version of that knife? As a leftie crafter, I'm always dismayed by seemingly simple tools that I either have to use with my non-dominant hand, or just go without. If anyone knows of a good place or site to buy quality left-handed tools, let me know. I've yet to find one that's more than novelty.

Do you need to remove the paper from the foam? I’m am brand new to this. Bought my first xps and want to learn. I like your manner., and methods.

I have a proxxon but can't use in in my room at the moment will set off the alarms.I do use knives but they can dull up and I go through a far number of blades ! Until I get a place to use my machine will use a variety of sharp knives!

Do you think that it would work to affix a block to the narrow side of the carpenter square so you can lay the blade against it as a guide to make straight downward cuts?

I got so XPS foam from my local hardware store but the only stuff they had was 1 inch thick. How could I reduce the thickness without sutting it up into small peices? BTW I do not have a wire cutter.

in Europe, one manufacture is called stryodur and make 3000cs to 5000cs, variety of depths, in uk the only manufacture is in birmingham

oooo that intro

What knife using solid blades would you suggest? Using it to cut 4'x8'x2" polystyrene sheets

Absolutely right regarding Olfa knives. The only one I have used since I discovered the company 20 years ago. Home depot sometimes doesn't have them with the other brands in the tool department - look in the paint department.

I'm a bit clumsy should I bother with burn resistant gloves for a hot wire cutter? Also if you accidentally cut slightly at an angle could you just cut a little thicker than the final idea and just sand one side down?

Excellent video, like always. Can't find any decent XPS in my area (or online that isn't stupidly priced), so sadly, my Proxon is sitting on a shelf... Question, since you use the foam cutter so often - do you find a loss of dimension in the cut? i.e. making 3" x 3" square, do you find yourself needing to add a small bit due to burn-off, to maintain measurements (say an extra 16th or 32nd of an inch)?

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