Petri, Feathering & other Effects with Alcohol Ink, Mica or Pigment Paste in Resin
Updated: Mar 11
This blog post might be helpful for those wanting to try different and very fun effects in resin. The various examples shared below are for reference purposes, if you'd like to try any of these styles.
Some people use the term petri effect when using all alcohol inks in resin. And when switching out the white alcohol ink instead to a white epoxy paste, some people refer to that as the feather or swirl or cloud effect. There are also examples below of getting similar unique effects without using any alcohol inks. There's many ways to create fun depth in resin using alcohol inks, or pigments, and different ways to manipulate them once in the moulds.
The best way to learn, is to start playing. You may need to play many times, with different amounts of ink drops in your resin, but it's important never to add too much ink. All resins behave differently from one another, so you'll only get to know how it will work, by playing with it. Experiment with small sizes first, as you are learning how your resin will work in your environment, and to get to know how much pigment to use. Artists go through a lot of trial and error when figuring out these techniques.
Some people find a medium-low viscosity resin (a medium viscosity can be made low-medium by warming up ahead), works best for these effects. If your resin is very low viscosity (thin like water), you may need to let it sit in the moulds for about an hour or two, (brand dependent) before you can pour the inks. Again you will have to practice to see what works best with your resin, and studio temperature, and pigments used. Most people have found that high viscosity resins (very thick consistency), do not tend to work as well with these types of techniques (example below). Again, the only way to know, is to try. There is no magic recipe for everyone, because everyone uses different products, has different temperatures, humidity levels and other factors that effect results.
It is not uncommon for people to find they get a lot of white blobs when trying these techniques, (white being the heaviest pigment). Years ago they seemed to be a fun part of the petri effect, but now many people prefer to create this style without the white blobs of that sink to the bottom of the mould. I don't mind a few blobs, they're part of the effect if not too many show. Blobbing can be from too much pigment or too cold a resin. And even after tons of trials, it can still occur. By practicing (like any art), you will get the hang of it, and figure out how much pigment is too much or too little. Another thing to be careful of, is if you use far too much alcohol ink or pigment, it may throw off the resin balance, and cause it not to cure properly, or you may end up with a mushy mess in the bottom of your mould. So, it's best to start with not too much ink/pigment, and work your way up to adding more as you experiment for different techniques.
For these effects, start by pouring your clear resin. In these first pieces, I used iCoat TP24 FC casting resin, in these hearts. I have over the past year, began to use an infrared digital thermometer, every single time I mix epoxy.
Important Note *** With iCoat epoxies, you will get best results, and you can achieve more consistent results, from not guessing the temperature. Epoxy resins always work best at correct temperatures, and they each have their own recommendations. You will get to know your resin timing and best qualities quicker, by always using an infrared digital thermometer, every time you use resin. Even after using resin for 30 years, iCoat owner (Tim), checks the temperature every single time he mixes epoxy. Never assume temperature of resin, or room. There's more on that subject in other blogs on our site.
Alcohol Inks in Resin (the Jacquard Pinata white alcohol ink was diluted with 99% isopropyl alcohol for these 9 hearts shown).
It's been about 4 years since I played with these techniques, but I do love seeing the everchanging and unique results. The iCoat TP24 FC, is a low-medium viscosity resin, and I wasn't sure if it might need to sit in moulds for a bit before adding the inks. But decided to experiment. I was working on a few things at the same time, so it may have sat in moulds for about 10 minutes max before I started adding the inks. The clear resin temperature was 80 F when mixed, and about 77-78 F once in moulds.
On these 9 hearts, I did one round of dropping alcohol inks (1 drop per section), followed by a round of dropping white alcohol ink (Jacquard Pinata Blanco white ink mixed with 99% isopropyl alcohol), 1 drop over top of the coloured ink drops. For the white in these hearts, I put white Pinata Blanco alcohol ink, in a needle tip bottle, then added the alcohol. Shook well, and dropped one drop of the white over the coloured inks. I repeated previous process of dropping colour ink over the white, and then another white drop over the colour. Then once all the hearts had inks added, I took a toothpick, and made swirls. Wipe off the toothpick each time you lift it out of the resin. Do not allow toothpick to touch bottom of the mould, as it can scratch your mould permanently, which will show on your piece (and every piece after).
Dilution of Jacquard Pinata Blanco white alcohol ink. The ratio I used to dilute the white ink, was roughly about 30% ink to roughly 70% alcohol, in a needle nose bottle. Shake really well after adding the two, and again throughout process. The white settles. I feel my dilution was too much, so next time I'll try experimenting again, but with about a 50/50 mix. I think (hope) I'll get the results I'm wanting (without getting too many white blobs on the bottom which I thankfully managed to avoid with these).
Another dilution method some use, more for the cloud type effect, is 50 drops of the Jacquard Pinata white to 1 oz of resin, in a cup.
Prior to creating these hearts, I did a test run in a deeper ring mould, with using straight white alcohol ink, and it was much too heavy for this resin. I may also have used to much pigment in general, and I ended up with a mushy mess in the bottom of the mould. So I knew I needed to lighten the white ink, by adding alcohol before creating the above hearts. How much you lighten the white, will depend on a lot of factors, so you will need to experiment a bit to find the correct ratio with products you are using.
Alcohol inks in resin (with Pinata white alcohol ink not diluted).
These coasters shown, I created over four years ago (January 2019), and the two hearts below them (I created August 2018), were often referred to as the petri style effect in resin. The white ink (jacquard pinata) had no isopropyl alcohol added. The resin used back then, is not one I carry anymore, but it was very thin (like water) consistency, so I had to let the resin sit in the moulds for about two hours (to allow viscosity to thicken a bit), before I could drop the inks. I did not swirl these after dropping the inks. I didn't use much white, and I left negative space, because I like seeing through the resin. The iCoat TP24 FC, is what I would try next for this effect.
Here are a few of the hearts I made (back in 2018), the same way as mentioned in the coasters coaster above.
This set of coasters I made with everything the same as above coasters (no alcohol added to white ink either) But here I used a medium viscosity resin (which I no longer carry, and that resin was not warmed up ahead. I dropped the inks right after pouring resin in to the moulds, as I didn't want this resin to sit and thicken more. As you can see the inks did not spread out as much in the medium viscosity epoxy (thicker consistency then the thinner resin used in above coasters). So the effect was not as desirable as previous set. I hope to try this with a warmed up iCoat Medium Viscosity (topcoating epoxy) soon, and the iCoat TP24 FC (casting epoxy). I'll post my results here when I do.
The ink spreads much more beautifully in the warmed up iCoat TP24 FC, as seen in hearts up top, without having to wait 2 hours. I hope to experiment soon with the iCoat Medium Viscosity epoxy, bottles pre-warmed up to about 80F, prior to mixing, as I think that viscosity may work well too. It will cool once in moulds. I'll add that to this post once I have time to try it. I know if cold, the inks would not spread as nice.
Some people really dislike working with alcohol inks. From what I have noticed, it's often because the type of ink can effect the finish. Also alcohol inks are not light fast, so they can fade, and some people found they faded fast. I found most people have good success using Jacquard Pinata Alcohol Inks, and Ranger Alcohol Inks.
Below, you will see a few other methods to get unique texture designs in resin. And you don't necessarily need always need alcohol inks to achieve these fun textured depth looks. Mica will not achieve the same look as alcohol inks, but it will add a pearlescent or other shiny effect in the areas it sits. Epoxy pigment pastes mixed with resin will work great.
Pigment Coloured Resin added to Clear Resin in moulds (no alcohol inks used in examples below).
These coasters, I made in May 2019, and instead of using alcohol inks, I used various pigments in resin. I poured clear resin into the moulds first. Then added lines of pigmented (some mica, some epoxy paste) resin. Then added the white which was a pigment paste mixed with resin (I just used a paper cup squeezed into spout shape to pour the lines). Then manipulated designs using a toothpick.
These days some people might refer to this as similar technique, called the swirl effect in resin (which many people will make with coloured alcohol inks dropped into clear resin, then pipe the white epoxy paste coloured resin. The white is often manipulated differently, and often into floral patterns.
A few more
examples (from coasters I made in 2019) of using pigmented resin poured into in to clear resin, then manipulating the coloured resin carefully through the clear.
And as you can see with the blue green coaster set, you don't always need to use a white. White is the heaviest pigment, so will give more of that texture depth look, but pigments have different weights and you can still achieve cool effects mixing other coloured resin too.
Floral effect coasters
This floral coaster example was made by Dea Snow. For floral and other patterns using similar mediums above, many people find it easier to get more control, by pouring the white coloured resin using a piping (icing type) bag (or ziplock bag), instead of pouring from a cup, in to the mould. Then use a toothpick or silicone tip brush, to manipulate into a floral or other pattern. Dea Snow shared loads of her helpful tips and great information on this style, please (see this blog post) called Resin tips/tools for resin floral coasters). This technique, does take lots of practice.
Remember to wipe off the tip (of manipulating tool) each time you pull it out of the resin, before using in next mould. And be careful not to drip on other pieces before wiping the tool.
Some people find the medium to low viscosity works for these floral coasters, so you can use the iCoat Medium Viscosity, but warm the bottles up to about 82 F prior to mixing. Use a digital thermometer so you're not guessing. If bottles get to warm, leave lids off and let cool prior to mixing.
I am also tempted to try using the iCoat TP24 FC for this technique, but the resin may need to sit in the moulds for a bit (maybe 1/2 hour to 1 hour), to thicken the viscosity prior to adding the colours. I hope to experiment with this and share info soon.
The Resin Feathering Technique, is another popular term some people use for similar effects with these mediums.
There are also some artists, who have used another version mixing these colour mediums (alcohol inks and/or pigments), for varying effects in resin.
You can add a bit of 99% isopropyl alcohol to your pigment coloured resins or, just the white paste coloured resin. Lots of experimenting (trial and error), created many cool versions of this technique/style, to get varying results.
Jennifer McKay from DreamDust Designs, was kind enough to show how she created some fun effects adding isopropyl alcohol drops to pigmented resin.
This video covers her "experimenting" with the Resin Feathering and Swirl Technique.
She shares all. I would suggest our iCoat TP24 FC casting resin for this project.
Here's another YouTube video by Jennifer McKay sharing her experiments and suggestions for Do's and Don'ts for the Resin Feathering and Swirl Technique. I would suggest trying out iCoat TP24 FC casting resin for this style.
Another YouTube video by Jennifer McKay, sharing her experience using a fine tip needle bottle vs toothpicks used in her previous videos. The video includes her experiences (good and bad/pros and cons), with experimenting with these styles. I would recommend trying out iCoat TP24 FC casting resin fit this technique.
As you can see there are so many different takes on this technique. There is no right or wrong way with art. But one thing to know, is these do take practice, but are so worth it once you achieve your desired results.
Have fun creating ;)