18 February 2017
Stages 2&3, Project 1 – Moulding from a surface (blog post 2)
***** continued from blog post 1 ********
I decided to carry out a series of experiments to determine how well texture can be reproduced with the following materials:
- Wetted leather
- ModRoc (plaster impregnated bandage)
- Starched fabric
- Rice paper
I left the leather to soak for about 15 minutes in warm water before moulding it over my chosen surface. I pulled the leather taught and left it secured with pins and clamps as it dried.
- Cost: Cheap. Although leather can be expensive, offcuts can be purchased relatively cheaply and the only other material required is water.
- Ease of use: Fiddly; the leather has to be kept taught while it dries, and needs to be in continual contact with the pattern. Pinning or some other means of securing is needed.
- Reproduction of surface texture/detail: Good, but not the most detailed.
- Handle: Remains pliable, although it does harden slightly after the wetting and drying procedure.
- Potential for colouring and working: Leather can be coloured with specialist dyes. It can be stitched, punctured and distressed.
SAMPLE 30: Leather stretched across homemade pattern used in sample 10
This was the pattern in which I had glued keys, coins and a nail onto a piece of wood. I simply stretched the leather over the surface using my fingers and various implements such as paintbrush handles and toothpicks, to work the leather into the crevices. I then left it in place until dry.
The result was almost like a ghost image. It reminded me of some of Eduardo Paolozzi’s reliefs, but on a smaller scale. The underside (suede side) of the leather had better defined shapes, as it was touching the objects (see below):
I only had one type of leather, which was thicker than I would have chosen. I’m sure a more accurate relief could be obtained with a thinner, softer hide, such as nappa leather.
SAMPLE 31: Leather stretched across a wooden spoon
For this sample, I used a wooden spoon, stretching the wet leather around it and holding it in place with drawing pins and paperclips to keep its taught. I left it until the sample was dry.
The result was good, but unremarkable (see below). Drying took several days.
The sample retained it shape well after the spoon had been removed.
SAMPLE 32: Leather shaped with a plastic spray bottle
I chose this bottle because it had an interesting ribbing on the handgrip. I started by simply stretching the leather over the bottle, but found that I needed elastic bands and string to keep it taught (see below). I wondered whether these would also mark the leather.
Opposite the ribbed area, I formed creases in the leather to make it fit around the bottle top. The finished result is shown below:
The leather held the creases and marks well, although as a sample, it’s not really very appealing. Maybe these techniques could be used in another context?
The ModRoc was easy to use. I cut it into appropriately sized strips for my project before momentarily emerging it in warm water before taking out and squeezing gently to remove excess water. The pre-impregnated plaster strips could then be laid across the textured surface. Where possible, I built up layers in different directions for added strength. I left the plaster to dry until it had completed it’s exothermic phase, then removed the mould or pattern before leaving it to dry completely. I used Vaseline as a release agent for all my ModRoc samples.
- Cost: Cheap and readily available (£1 for a roll from the NUA student shop)
- Ease of use: Not difficult, and certainly easier than casting plaster. A plastic sheet is useful for protecting the work surface.
- Reproduction of surface texture/detail: Good, however where the pieces of fabric join, there are ‘lumps and bumps’ and inevitable surface texture caused by the fabric itself.
- Handle: Rigid and shell-like.
- Potential for colouring and working: Finished work could be varnished or painted. Areas where the plaster is not as thick could possibly be stitched or punctured, although there is a risk of cracking.
SAMPLE 33: ModRoc with flattened aluminium pie dish
I flattened a pie dish to get more texture into it’s surface before moulding. The result is shown below:
It would be possible to trim the rough edges with scissors, or a scalpel, if desired. A lovely sample,
SAMPLE 34: ModRoc with fruit squash bottle
I moulded around the bottom third of a squash bottle. However, it was not until I attempted to remove the cast, that I realised that the bottle was tapered inwards, causing the cast to crack as it was removed. Something to watch for in future.
SAMPLE 35: ModRoc with crushed tin can
This was a different can, but the same idea which was used in sample 17. Unfortunately, it was not a success. There was undercutting, particularly i the ring-pull area, which meant the cast cracked and broke when the pattern was removed (see below):
SAMPLE 36: ModRoc with bubble wrap
I used the same piece of bubble wrap which I had used for sample 29. The result was stunning. Not only was the surface in contact with the plastic textured, so was the reverse surface. There were areas of smoothness, areas of fabric textured roughness and creases reflecting those in the plastic itself.
The result was a firm crease shaped ‘shell’ in a wave shape (although a different shape or flat could easily have been formed). I have explored this sample in a series of observational drawing in my sketchbook on pages 29-30.
SAMPLE 37: ModRoc moulded around a yoghurt pot
This was a simple idea, not to Cover the yoghurt pot entirely, but just to make a bridge over the open top, which could be easily removed when dry. The result was a cup-shaped cast which resembled fabric draped across a jam jar (see below)
Turning the piece over, gave a ‘dish’ with a convex dome in the centre.
Thinking about traditional Japanese packaging, I had the idea of using it as a container for marbles (see below):
It looks almost like a waterlily or lotus flower. Sketches and discussion of possible developments have been made in my sketchbook (see pages 42-45).
SAMPLE 38: ModRoc moulded egg box
Despite applying vaseline, the casting did not release properly, and I had to pull pieces of cardboard off the cast. This was because the egg box paper was so porous, that the vaseline soaked in, and effectively did not form a barrier. Nevertheless it is a good casting and a very faithful representation, which I have mistaken for a real egg box several times!
This sample is explored in my sketchbook on page 21.
SAMPLE 39: ModRoc with water balloon and plastic fork
An unlikely combination, but I was thinking also about using the modRoc as a joining method.
I first filled up a water balloon with water then covered most of it with the modRoc (leaving a small gap near the tied balloon opening). I then wrapped and joined the fork. Finally, I also incorporated some pieces of lace and cotton thread. When the ModRoc was dry, I pierced the balloon with a pin to let out the water and I removed it.
I can’t help think that this sample resembles a lamb or goat head, with the water release hole symbolising the mouth.
I’m really pleased with the extra texture added by the fibre and thread scraps. Although they are partially covered by the plaster, it is a good way of integrating them into a mould, giving the impression of hair or fur.
SAMPLE 40: ModRoc and modelling balloons
I wanted to created an inter-twined sculpture of two balloons.
I did not bother with a release agent, because I decided that I would not be attempting to remove the balloon from the casting. First I moulded a round a single balloon, which I had tied together to form a looped shape (see below):
When this first sample was completely dry, I threaded another modelling balloon through and tied it, before starting to cover with modRoc, as before. I also added some string fibres for extra texture.
I had fun configuring this sample in lots of different ways and photographing it. In some positions, it appeared acrobatic, others like two linked arms.
I used laundry starch which I first dissolved in water before soaking cotton muslin fabric. I then laid the fabric over the pattern/mould and allowed the fabric to dry completely before removing it.
- Cost: The starch is cheap and readily available (£2.05 for 200g from Amazon)
- Ease of use: Not difficult, however the instructions were ambiguous, stating “scoops” without detailing the volume or weight.
- Reproduction of surface texture/detail: Not particularly well defined. Possibly because the starch solution which I had used was not sufficiently concentrated. A more closely woven fabric may also have worked better.
- Handle: Stiffened, but still pliable.
- Potential for colouring and working: Would be easy to sew into tear or puncture. However, I suspect that handling would remove the stiffness and any shape would be lost.
SAMPLE 41a): Starched fabric stretched over a homemade pattern of keys, coins and nail (see sample 10)
I used the same pattern which I had made for sample 10, and which I had also used for sample 30. Initially, I felt that the results were disappointing; I could barely make out the shapes of the objects. However, in certain contexts, maybe this could be a desirable effect? The sample looks almost “ghostly”, and you have to use your imagination to decipher what the objects might have been. There is the feeling of just a fading trace of something lost.
Not surprisingly, the fabric was stained by the wood and metal. However, this might be desirable effect in some instances.
SAMPLE 41b): Starched fabric with bubble wrap
This was the same curved piece of bubble wrap which I had used for samples 29 and 30. When the fabric was removed, it retained the shape of the bubbles, but not the overall curved of the wrap. I was a little disappointed in this respect.
I used strips of wetted rice paper which I laid across the pattern/mould. The starch in the paper acts like glue, so when dry, the paper sticks together and takes the form of the object.
- Cost: Not particularly cheap (approx. £6 for 8 x 12″x54″ sheets), however economical, providing the project is small.
- Ease of use: Very easy.
- Reproduction of surface texture/detail: Good, although not as well defined as ModRoc.
- Handle: Stiffened, but still pliable.
- Potential for colouring and working: Would be easy to stitch, puncture or tear, however handling is likely to degrade the moulded surface. Colouring would have to be done whilst wet, before moulding.
SAMPLE 42: Rice paper with flattened aluminium pie dish
This was the same dish which I had used for sample 33, so it was nice to be able to compare results with the different materials. I made an observational sketch of this sample on page 28 of my sketchbook.
I was very surprised how well this moulding worked with nothing more than wetted rice paper. Unlike sample 33 (made from ModRoc), which is rigid, this sample is pliable, workable and much lighter weight. I would have liked to make some more samples from rice paper, however, I ran out of time.
I had some latex already, so I thought I would try it. I liked the idea that it could be coloured with water-based paint and is soft enough to be sewn into. If used alone, the resulting skin is stretchy. A firm mould/casting can be formed by adding a layer of fabric gauze. A sprinkling of talcum powder prevents the finished latex skin from sticking to itself.
Although latex can be applied by brushing on or dipping, to dip would have required a large amount of latex to fill a suitably-sized contained, so I opted for the brushing technique.
- Cost: Liquid Latex (skin safe) is quite expensive (£13.99/litre from Amazon), but it is economical in the quantity used for each mould.
- Ease of use: Very easy, although it has to dry between each layer, which makes the whole process time-consuming. It also damages the brush used to apply it, but forming a skin around each bristle which builds up over time. A release agent is not necessary. Due to it’s stretchiness, it can be used where there is a undercutting (although deeply undercut surfaces were not successful).
- Reproduction of surface texture/detail: Excellent – every detail is captured.
- Handle: Pliable and rubbery, forming a stretchy skin.
- Potential for colouring and working: It dries to a rather unattractive semi-opaque off-white, which I have found changes to an even less attractive yellowish brown over time. However, it can be successfully combined with acrylic paint before application, which also speeds the drying time.
SAMPLE 43: Latex mould of a polystyrene meat tray
The tray was the same one which I used for sample 26 and had a diamond-shaped base. I started by brushing layers of natural latex onto the surface letting each layer dry between applications. Numerous applications were made over approximately 2 days. Because I don’t find the natural latex colour very attractive, I decided to make the final layer coloured by incorporating some acrylic paint. This gave amazing results (see below: tray left, moulding to the right)
The diamond showed up as the natural beige colour, where the latex was more thickly applied, but where it was thinner, it was sufficiently transparent as to allow the brown paint to show through, giving a really interesting two-tone effect.
The application of the latex is not uniform, although I think this adds to the samples interest with texture and colour variation.
Because I liked this sample so much, I decided to make another series using the same two-colour technique. I have also made some observational drawings and analogies on pages 24-26 of my sketchbook.
SAMPLE 44: Latex mould of a chard leaf
Using the same method as above I applied layers of latex to a chard leaf from my garden.
The leaf was quite floppy and highly textured with a lot of undercutting, so I wasn’t particularly optimistic about the results. However, the finished sample is an excellent replica of the original surface, made even more dramatic by the use of a final coat of latex coloured with acrylic paint.
The sample is also highly tactile and stretchy. I made observational drawings on page 22 of my sketchbook.
Despite initially loving this sample, I have been disappointed with how the uncoloured latex has discoloured over time (see below)
In future, I shall not leave any latex in it’s natural (uncoloured) state.
SAMPLE 45: Latex mould of an avocado skin
This was a beautiful casting which captured the subtleties of the surface. Again, I used a natural latex layers initially, followed by a final layer coloured with green acrylic paint. The outer edge is where the layer made a “mould” of the plastic bag which I was resting the avocado skin! It could easily be trimmed off with a scalpel or scissors, however, I left it because it is an interesting surface in it’s own right.
SAMPLE 46: Latex mould of a homemade pattern using staples
This was the same pattern that I had used for sample 13, simply brushed with layers of latex. Unfortunately, the paper stuck to the latex, and the sample tore as I tried to remove it (possibly due to undercutting).
SAMPLE 47: Latex mould taken from a crushed can
Taking inspiration from sample 17, I coated a crushed can with layers of latex. Unfortunately, due to the undercutting around the ring-pull area, it tore as I tried to remove it from the mould. It was also quite a “ragged” sample because of how the latex has spilled over the edge of the can and onto the plastic sheet which it was resting on.
SAMPLE 48: Latex mould taken from a flattened aluminium pie dish
Taking inspiration from samples 33 and 42, I covered a similar flattened pie dish with layers of latex. There is a hole in the final sample because the piece dish was punctured as latex ran through. However, the sample is really interesting, especially in the two-colour version (see below)
It reminded me very much of a biological specimen, with the natural latex resembling fat. I have discussed this in connection with potential development work and developed analogies on pages 47-52 of my sketchbook.
As there is a lot of thickness of natural (uncoloured) latex in this sample, the discolouration over time has been particularly marked (see below, after a few weeks). I find the brown colour unattractive, so I will colour all my latex in future.
SAMPLE 49: Latex mould taken from a scored polystyrene meat tray
I scored a plastic meat tray with a scalpel before applying the latex in layers using the same method as before. It was the same mould which I used in sample 18 (from which I had taken a press-mould using air-drying clay).
I really like the surface texture created, however, some of the polystyrene stuck to the latex as I removed the casting. It was not serious, however it is visible on the finished sample.
I bought some general purpose condensation cure silicone, consisting of base and catalyst. It was necessary to throughly mix these components throughly before casting. So that I could make sure that it was mixed properly, I bought some pigment which I added at the same time. I didn’t have the facilities to cast by dipping my object/surface into the silicone, so I opted for pouring it on. The mistake I made was that the silicone was too runny and tended to run off the surface (at least in parts) before it had set. I should have purchased a thixotropic agent (an additive which makes the silicone thicker, and suitable for this type of application). Nonetheless, I got some interesting results, and because I had not not added the thixotropic agent, some very thin and delicate membranes. An advantage with silicone is that it only adheres to itself, so unless a silicone mould is being used, a released agent is not needed.
- Cost: The general purpose 1.1 litre kit of condensation cure silicone (1 litre base + 0.1litre catalyst) which I purchased from MB fibreglass cost £16.67. The small pot of pigment (enough for this quantity of silicone) cost about £2. Whilst not cheap, I was able to make several samples, certainly enough to give me a feel for working with the material.
- Ease of use: Very easy, although it would have been better if I’d added a thixotropic agent.
- Reproduction of surface texture/detail: Excellent – every detail is captured.
- Handle: Pliable and rubbery, forming a stretchy skin. However, I feel that it is more fragile and prone to tearing than latex.
- Potential for colouring and working: Pigment (if desired) must be added before casting. Lots of colours and finishes are available. The finished material can be stretched, stitched or punctured.
SAMPLE 50: Silicone mould of a chard leaf
I decided to attempt moulding the chard leaf because of my success with latex in sample 44. However, the silicone was less viscous than the latex, it tended to run off the surface leaving a lacy pattern with many holes (see below), rather than a continuous skin.
As you can see from the photo collage, I enjoyed experimenting by viewing the sample under different lighting conditions and seeing what shadows it would cast. I also explored the sample through sketches (see sketchbook page 48-49), both observationally and to explore the context in which this sample might be developed further.
The downside of this sample is that this sample is extremely fragile. However, this is also part of it’s appeal and it is because of it’s intricacy and delicacy that it is one of my favourite samples.
SAMPLE 51: Silicone mould of bubble wrap
I used the same piece of bubble wrap as I had to make samples 29 (papier mache), 36 (modRoc) and 42 (starched fabric). Once again, because the silicone was not viscous enough for my application method, it tended to run off the surface. However, this resulted in some areas of extremely thin membranes, as well as some areas where holes formed (see below):
Although extremely delicate, this is a very attractive surface. The silicone has captured every detail of the creases in the bubble wrap plastic, yet in other areas, it is smooth and shiny. I like the different thicknesses of silicone and the “breakthrough” areas.
Lit from behind, the sample gives an interesting effect, with the thin areas of letting through more light than the areas where the silicone has pooled (see below):
SAMPLE 52: Silicone cast taken from an air-drying clay mould of avocado skin
I had already made a mould of the avocado skin using air-drying clay, into which I poured the silicone.
Because the air-drying clay was hard, the only way to remove the casting from the mould would have been to break the clay! However, the clay was rock hard and not very brittle. A gentle tap with a hammer was not sufficient, so I decided to give up rather than risk injury.
SAMPLE 53: Silicone cast of polystyrene meat tray
This was an identical meat tray to the one used for samples 26 (carton Pierre) and sample 43 (latex).
I was really pleased with this casting. A pliable surface which could be manipulated (for example by wrapping around another object), and an excellent replica of the surface.
SAMPLE 54: Silicone casting of air-drying clay mould of knitting sample (see sample 16)
I altered sample 16 by building up a wall of clay to make a mould which would contain the silicone.
You can see from the mould (above) that minute pieces of silicone stuck to the air-drying clay and stained the mould. It was also very difficult to remove (although I did manage eventually!) If I was repeating this casting, I would opt to use kiln-fired clay instead (which remains pliable unless fired, so is easy to remove by peeling back).
The results were amazing (see below) – astounding levels of detail, right down to the texture of the fibres on the string!
Plaster of paris casting using pressed clay moulds:
This was the last set of moulded surface samples I made. They came about because I had been using plaster of paris for project 2 (casting an internal surface) and had plenty left over. After the difficulties with using air-drying clay as a press mould, I thought of trying kiln-fired clay, which being pliable, can been peeled away after casting. This means that it is possible to make a usable mould even where there is undercutting. Guided by Brooks (Brooks, 2005: 31), I opted not to use a release agent on my patterns (the exception being the mould made from a piece of bark).
Making the moulds first was a similar process to using the air-drying, polymer and paper clays. I cut off and rolled up a thick piece of the clay, then made an impression with the pattern of my choice. If it didn’t look as if it would be deep enough to hold the plaster, I rolled up a “sausage” of clay and attached it around the sides to make a wall.
I then mixed up some plaster of paris. I didn’t weigh the amount of water and plaster, I just added the plaster to the water filled bucket until “islands” of plaster appeared on the top of the water. I squeezed out lumps with my hand, then poured the plaster firstly into a jug, then into my moulds. I waited until the plaster was set before peeling away the clay.
In general, I was delighted by the range of surfaces which I was able to create and the level of detail captured. I noted however, that the clay tended to stain the surface of the plaster brown. This would not be an issue if the sample were to be painted, or some other surface treatment applied.
- Cost: The kiln-fired clay cost £8.25 for 5kg from Amazon. There was enough to make all the moulds shown above, and it will probably be reusable. The plaster of paris cost £23 for 25kg. I only used about 1/10th of the pack for these samples.
- Ease of use: The clay was very easy to use, being more pliable than the air-drying and polymer clays which I used. The plaster was straightforward, but extremely messy (especially as I am working in a domestic environment). I found that it can be difficult to make up the correct quantity (I usually made too much), and a dust mask and eye protection are needed during preparation.
- Reproduction of surface texture/detail: Excellent – every detail is captured. It is a bonus that undercut samples can be used.
- Handle: After a few hours it is touch-hard, yet still fragile. The plaster dries very hard over a period of days (depending on the thickness), but retains a powdery, porous surface.
- Potential for colouring and working: Dry plaster casts can be painted with acrylic paint, stained with shoe polish or varnished.
SAMPLE 55: Plaster of paris cast from moulding of a candle holder
I used the same metal candle holder that I had used for sample 12 (air-drying clay) and sample 21 (mouldable polymer) as a pattern. I made a mould by pressing the surface into a slab kiln drying clay. The plaster cast which I took from the mould gave good detail, however it was difficult to get even pressure when making the mould (I had to roll the candle holder in the clay), and this is reflected in the plaster cast.
The edges of this cast are a bit messy, because I was not too particular when making the walls of my mould. Presumably they could be filed down or sanded (although this would be messy).
SAMPLE 56: Plaster of paris cast from moulding of a seashell
I was very surprised how well this cast came out, picking up every detail, it could almost be mistaken for another shell!
SAMPLE 57: Plaster of paris cast from moulding of some bark
The pattern was made from a piece if bark to which I applied a dusting of talcum powder as a release agent before taking a mould using the kiln fired clay.
I built up a wall of clay around the impression to make a mould into which I could pour the liquid plaster.
The resulting cast came out very well, being heavily textured and reflecting the relief pattern of the bark. The only problem was that there were some small residual pieces of bark stuck in the clay and in the cast. They would probably be painted over.
SAMPLE 58: Plaster of paris cast from moulding of a piece of burlap
I cut a small piece of burlap and pressed it into a slab of clay to make a mould. The cast was a a lovely representation of the fabric.
SAMPLE 59: Plaster of paris cast from textured surface made with clothes pegs
I made a simple round impression in the clay with a lid, then textured it but pushing the end of a clothes peg into the surface (see below)
The resulting cast (being the negative of these impressions) was a most intriguing surface. The image below shows the cast from above:
And in this image it is viewed from the side:
This example shows how a mundane object can be used to make a truly stunning and unusual surface (see also, page 8 of my sketchbook for an observational drawing)
SAMPLE 60: Plaster of paris cast from textured surface made with a spoon handle
This sample was made using a very similar technique to sample 59, except the implement used to make the texture was a rounded handle end of a plastic spoon, which I twisted as I inserted it into the clay. The photo below shows the two press-clay moulds for samples 59 and 60 (which were made together in a single piece).
The finished cast was a unique textured surface, which reflects the dynamics of the way in which the clay impression was made.
There is an observational drawing on page 8 of my sketchbook, which together with sample 59, places these textured surfaces in he context of an idea for development of textures slabs could be juxtapositioned (i.e. “tiled”).
SAMPLE 61: Plaster of paris mould of a textured surface made with piping cord
The clay mould for this sample was a bit ad-hoc. I took a slab of clay and pressed it roughly flat with my fingers before pushing down lengths of piping cord in a striped pattern.
The resulting cast reflects not just the detail of the cord fibre, but also the undulations of my finger marks. It is a bumpy, uneven cast which has element of uniformity from the roughly parallel string impressions. It has spontaneity which add to it’s appeal.
Brooks, N. (2005) Moulding and casting. Marlborough. The Crowood Press Ltd.