I made Professor Gilderoy Lockhart’s Dueling Club Cape (way back in 2006) using Rayon/Silk velvet, Fiber Etch and Procion MX dyes.
Fiber Etch is SUPER COOL. Let me explain:
Devoré literally means devour! This technique is used to eat away certain kinds of fiber, specifically paper/wood/plant-based fibers like cotton, rayon, linen, bamboo, etc.
It uses a mild acid (sodium hydrogen sulphate aka sodium bisulphate - it’s also used for pH balance in swimming pools) activated by heat to burn cellulose away while leaving other things (protein-based things from animals - like silk, wool, leather, your fingers - or plastic-based things like polyester) alone.
Mostly alone. If you leave it long enough, it’ll slowly start burning away silk or your fingers, so don’t be foolish with it. Read the package, wear plastic gloves, don’t breathe deeply of it, and if you’re in a particularly safe science mood, you could keep a weak base (like baking soda) around to neutralize spills.
You can buy it at some craft stores, fiber art stores (like quilting or weaving type places), art suppliers and online at Dharma Trading for instance.
A nifty side-effect of this is that you can use Fiber Etch to determine fiber content - like to test if a shiny smooth satin fabric was made from rayon or silk, for example.
I practiced the whole process a couple times on scrap pieces of fabric before launching into this. As you’ll see, there are a couple steps where things can go wrong - it is a technique that requires some practice and getting the hang of first.
For etching velvet to be used in this cape, I started with a rayon/silk blend velvet. This is pretty commonly called just plain “silk velvet” in lots of stores, but that’s so misleading. Velvet like this isn’t made with 50% rayon and 50% silk threads all blended together, it’s actually a silk backing (the flat woven part of the fabric) with a rayon pile (the fluffy part). Think of velvet like a carpet.
When you eat away the fluffy rayon with Fiber Etch, you’re left with the flat silk backing - the fabric is etched.
You can also do this with rayon/silk satin that’s been specially woven so that the rayon portion is shiny and will leave behind a more matte silk portion.
Or, if you want to use it on 100% cotton/rayon/plant-fabric it can eat a hole right through it and make eyelet lace, cut-out effects, etc. It’s best to edge the fabric with 100% polyester-thread embroidery or fabric paint in that case to keep nice clean lines: Creating Chemical Cutwork on Threads Magazine.com
Fabric treatments and finishes can get in the way of the chemical process, so pre-washing with detergent (synthrapol is best) and hot water is highly recommended.
I sketched out a tile-able (see my Tali fabric design tutorial for what that means) pattern on scrap paper with Sharpie markers - enough to fit under my largest pattern pieces. I left my fabric un-dyed so that it would be more transparent and easier to see the design under it.
Then simply taped it all down and carefully applied Fiber Etch over the design. You can tell where you’ve applied it even after it’s dried, but it’s best to be systematic so you don’t miss places. Also, make sure you’re not leaning over or dragging yourself through the Etch, so start in one corner and plan your approach.
You put the Etch on the fluffy/pile side of the velvet.
Dry the Etch - waft your hair dryer over it. For big sections, you might want to dry as you go.
Then iron on medium heat on the reverse side (the flat backing side) until the Etch lines are “lightly toasted”. Make sure you get all the lines evenly toasted but not burnt. The Etched bits will feel slightly crispy under a fingernail. (You can also try to do this step in the clothes dryer - I’m more comfortable doing this under my direct control).
Then wash (I always hand wash this kind of thing) and gently agitate the Etched lines so the velvet pile crumbles away.
This is obviously a different project, but you get the idea of what the etching looks like before dyeing.
Another plug here to encourage people, if possible, to use the right kind of dye on the right kind of fabric rather than boiling everything in RIT…
It’s been almost 10 years since I made this cape! I don’t remember exactly what dye I used, but the general thought was to focus on dyeing the fiber in the pile (rayon) and let the silk be a slightly different colour/less saturated if it wanted to.
Just like with the Etch - rayon (cellulose) and silk (protein) like different things when being dyed. But both of them do fairly well with a Procion MX dye (this is a good, general purpose kind of dye, awesome on cotton and other plant-based fibers, and pretty good on silk, just not as saturated and a bit more unpredictable in colour on them). This is exactly what I was going for on my cape.
As much as I dislike RIT, this is actually one of the times you might use it - it’s a disperse dye and is not a bad choice for fiber blends like this. It’s just… the colours aren’t as nice or predictable or stable, it runs and looks muddy, etc. By all means test though, I never argue with a good result :)
Since plant fibers like different dyes from protein fibers you can also use this to stunning advantage and dye the rayon one colour and the silk another! There’s a specific brand called “Alter Ego” that you can do this with.
I like my cape. The etched lines could be neater in places and the scale of my design is a little too big, but the colour is good and the feel of it is luxurious (seriously this thing is soft and light and silky like an otter).
In Harry Potter and the chamber of secrets, in the Duelling Club scene. When it’s Harrys turn to duel Draco, Harry uses the spell
Rictusempra Which is the tickling charm so in theory Draco should have been rolling around on the floor laughing but in the movie he is thrown across the room, landed on the floor only to frown and be picked up by snape?!